In [4]:
import os
# !pip install seaborn
In [12]:
# Our bot would like to know who's logged into the computer
# Where can we access environment variables
# try `os.e<tab>` or `os?` or `help(os)` to look for an Operating System feature like environment variables
help(os)
Help on module os:
NAME
os - OS routines for NT or Posix depending on what system we're on.
MODULE REFERENCE
https://docs.python.org/3.5/library/os
The following documentation is automatically generated from the Python
source files. It may be incomplete, incorrect or include features that
are considered implementation detail and may vary between Python
implementations. When in doubt, consult the module reference at the
location listed above.
DESCRIPTION
This exports:
- all functions from posix, nt or ce, e.g. unlink, stat, etc.
- os.path is either posixpath or ntpath
- os.name is either 'posix', 'nt' or 'ce'.
- os.curdir is a string representing the current directory ('.' or ':')
- os.pardir is a string representing the parent directory ('..' or '::')
- os.sep is the (or a most common) pathname separator ('/' or ':' or '\\')
- os.extsep is the extension separator (always '.')
- os.altsep is the alternate pathname separator (None or '/')
- os.pathsep is the component separator used in $PATH etc
- os.linesep is the line separator in text files ('\r' or '\n' or '\r\n')
- os.defpath is the default search path for executables
- os.devnull is the file path of the null device ('/dev/null', etc.)
Programs that import and use 'os' stand a better chance of being
portable between different platforms. Of course, they must then
only use functions that are defined by all platforms (e.g., unlink
and opendir), and leave all pathname manipulation to os.path
(e.g., split and join).
CLASSES
builtins.Exception(builtins.BaseException)
builtins.OSError
builtins.tuple(builtins.object)
stat_result
statvfs_result
terminal_size
posix.sched_param
posix.times_result
posix.uname_result
posix.waitid_result
error = class OSError(Exception)
| Base class for I/O related errors.
|
| Method resolution order:
| OSError
| Exception
| BaseException
| object
|
| Methods defined here:
|
| __init__(self, /, *args, **kwargs)
| Initialize self. See help(type(self)) for accurate signature.
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __str__(self, /)
| Return str(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| characters_written
|
| errno
| POSIX exception code
|
| filename
| exception filename
|
| filename2
| second exception filename
|
| strerror
| exception strerror
|
| ----------------------------------------------------------------------
| Methods inherited from BaseException:
|
| __delattr__(self, name, /)
| Implement delattr(self, name).
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __repr__(self, /)
| Return repr(self).
|
| __setattr__(self, name, value, /)
| Implement setattr(self, name, value).
|
| __setstate__(...)
|
| with_traceback(...)
| Exception.with_traceback(tb) --
| set self.__traceback__ to tb and return self.
|
| ----------------------------------------------------------------------
| Data descriptors inherited from BaseException:
|
| __cause__
| exception cause
|
| __context__
| exception context
|
| __dict__
|
| __suppress_context__
|
| __traceback__
|
| args
class sched_param(builtins.tuple)
| Current has only one field: sched_priority");
|
| sched_priority
| A scheduling parameter.
|
| Method resolution order:
| sched_param
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| sched_priority
| the scheduling priority
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 1
|
| n_sequence_fields = 1
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class stat_result(builtins.tuple)
| stat_result: Result from stat, fstat, or lstat.
|
| This object may be accessed either as a tuple of
| (mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime)
| or via the attributes st_mode, st_ino, st_dev, st_nlink, st_uid, and so on.
|
| Posix/windows: If your platform supports st_blksize, st_blocks, st_rdev,
| or st_flags, they are available as attributes only.
|
| See os.stat for more information.
|
| Method resolution order:
| stat_result
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| st_atime
| time of last access
|
| st_atime_ns
| time of last access in nanoseconds
|
| st_blksize
| blocksize for filesystem I/O
|
| st_blocks
| number of blocks allocated
|
| st_ctime
| time of last change
|
| st_ctime_ns
| time of last change in nanoseconds
|
| st_dev
| device
|
| st_gid
| group ID of owner
|
| st_ino
| inode
|
| st_mode
| protection bits
|
| st_mtime
| time of last modification
|
| st_mtime_ns
| time of last modification in nanoseconds
|
| st_nlink
| number of hard links
|
| st_rdev
| device type (if inode device)
|
| st_size
| total size, in bytes
|
| st_uid
| user ID of owner
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 19
|
| n_sequence_fields = 10
|
| n_unnamed_fields = 3
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class statvfs_result(builtins.tuple)
| statvfs_result: Result from statvfs or fstatvfs.
|
| This object may be accessed either as a tuple of
| (bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flag, namemax),
| or via the attributes f_bsize, f_frsize, f_blocks, f_bfree, and so on.
|
| See os.statvfs for more information.
|
| Method resolution order:
| statvfs_result
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| f_bavail
|
| f_bfree
|
| f_blocks
|
| f_bsize
|
| f_favail
|
| f_ffree
|
| f_files
|
| f_flag
|
| f_frsize
|
| f_namemax
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 10
|
| n_sequence_fields = 10
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class terminal_size(builtins.tuple)
| A tuple of (columns, lines) for holding terminal window size
|
| Method resolution order:
| terminal_size
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| columns
| width of the terminal window in characters
|
| lines
| height of the terminal window in characters
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 2
|
| n_sequence_fields = 2
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class times_result(builtins.tuple)
| times_result: Result from os.times().
|
| This object may be accessed either as a tuple of
| (user, system, children_user, children_system, elapsed),
| or via the attributes user, system, children_user, children_system,
| and elapsed.
|
| See os.times for more information.
|
| Method resolution order:
| times_result
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| children_system
| system time of children
|
| children_user
| user time of children
|
| elapsed
| elapsed time since an arbitrary point in the past
|
| system
| system time
|
| user
| user time
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 5
|
| n_sequence_fields = 5
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class uname_result(builtins.tuple)
| uname_result: Result from os.uname().
|
| This object may be accessed either as a tuple of
| (sysname, nodename, release, version, machine),
| or via the attributes sysname, nodename, release, version, and machine.
|
| See os.uname for more information.
|
| Method resolution order:
| uname_result
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| machine
| hardware identifier
|
| nodename
| name of machine on network (implementation-defined)
|
| release
| operating system release
|
| sysname
| operating system name
|
| version
| operating system version
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 5
|
| n_sequence_fields = 5
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
class waitid_result(builtins.tuple)
| waitid_result: Result from waitid.
|
| This object may be accessed either as a tuple of
| (si_pid, si_uid, si_signo, si_status, si_code),
| or via the attributes si_pid, si_uid, and so on.
|
| See os.waitid for more information.
|
| Method resolution order:
| waitid_result
| builtins.tuple
| builtins.object
|
| Methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| __reduce__(...)
| helper for pickle
|
| __repr__(self, /)
| Return repr(self).
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| si_code
|
| si_pid
|
| si_signo
|
| si_status
|
| si_uid
|
| ----------------------------------------------------------------------
| Data and other attributes defined here:
|
| n_fields = 5
|
| n_sequence_fields = 5
|
| n_unnamed_fields = 0
|
| ----------------------------------------------------------------------
| Methods inherited from builtins.tuple:
|
| __add__(self, value, /)
| Return self+value.
|
| __contains__(self, key, /)
| Return key in self.
|
| __eq__(self, value, /)
| Return self==value.
|
| __ge__(self, value, /)
| Return self>=value.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __getitem__(self, key, /)
| Return self[key].
|
| __getnewargs__(...)
|
| __gt__(self, value, /)
| Return self>value.
|
| __hash__(self, /)
| Return hash(self).
|
| __iter__(self, /)
| Implement iter(self).
|
| __le__(self, value, /)
| Return self<=value.
|
| __len__(self, /)
| Return len(self).
|
| __lt__(self, value, /)
| Return self<value.
|
| __mul__(self, value, /)
| Return self*value.n
|
| __ne__(self, value, /)
| Return self!=value.
|
| __rmul__(self, value, /)
| Return self*value.
|
| count(...)
| T.count(value) -> integer -- return number of occurrences of value
|
| index(...)
| T.index(value, [start, [stop]]) -> integer -- return first index of value.
| Raises ValueError if the value is not present.
FUNCTIONS
WCOREDUMP(status, /)
Return True if the process returning status was dumped to a core file.
WEXITSTATUS(status)
Return the process return code from status.
WIFCONTINUED(status)
Return True if a particular process was continued from a job control stop.
Return True if the process returning status was continued from a
job control stop.
WIFEXITED(status)
Return True if the process returning status exited via the exit() system call.
WIFSIGNALED(status)
Return True if the process returning status was terminated by a signal.
WIFSTOPPED(status)
Return True if the process returning status was stopped.
WSTOPSIG(status)
Return the signal that stopped the process that provided the status value.
WTERMSIG(status)
Return the signal that terminated the process that provided the status value.
_exit(status)
Exit to the system with specified status, without normal exit processing.
abort()
Abort the interpreter immediately.
This function 'dumps core' or otherwise fails in the hardest way possible
on the hosting operating system. This function never returns.
access(path, mode, *, dir_fd=None, effective_ids=False, follow_symlinks=True)
Use the real uid/gid to test for access to a path.
path
Path to be tested; can be string or bytes
mode
Operating-system mode bitfield. Can be F_OK to test existence,
or the inclusive-OR of R_OK, W_OK, and X_OK.
dir_fd
If not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that
directory.
effective_ids
If True, access will use the effective uid/gid instead of
the real uid/gid.
follow_symlinks
If False, and the last element of the path is a symbolic link,
access will examine the symbolic link itself instead of the file
the link points to.
dir_fd, effective_ids, and follow_symlinks may not be implemented
on your platform. If they are unavailable, using them will raise a
NotImplementedError.
Note that most operations will use the effective uid/gid, therefore this
routine can be used in a suid/sgid environment to test if the invoking user
has the specified access to the path.
chdir(path)
Change the current working directory to the specified path.
path may always be specified as a string.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
chmod(path, mode, *, dir_fd=None, follow_symlinks=True)
Change the access permissions of a file.
path
Path to be modified. May always be specified as a str or bytes.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
mode
Operating-system mode bitfield.
dir_fd
If not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that
directory.
follow_symlinks
If False, and the last element of the path is a symbolic link,
chmod will modify the symbolic link itself instead of the file
the link points to.
It is an error to use dir_fd or follow_symlinks when specifying path as
an open file descriptor.
dir_fd and follow_symlinks may not be implemented on your platform.
If they are unavailable, using them will raise a NotImplementedError.
chown(path, uid, gid, *, dir_fd=None, follow_symlinks=True)
Change the owner and group id of path to the numeric uid and gid.\
path
Path to be examined; can be string, bytes, or open-file-descriptor int.
dir_fd
If not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that
directory.
follow_symlinks
If False, and the last element of the path is a symbolic link,
stat will examine the symbolic link itself instead of the file
the link points to.
path may always be specified as a string.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
If follow_symlinks is False, and the last element of the path is a symbolic
link, chown will modify the symbolic link itself instead of the file the
link points to.
It is an error to use dir_fd or follow_symlinks when specifying path as
an open file descriptor.
dir_fd and follow_symlinks may not be implemented on your platform.
If they are unavailable, using them will raise a NotImplementedError.
chroot(path)
Change root directory to path.
close(fd)
Close a file descriptor.
closerange(fd_low, fd_high, /)
Closes all file descriptors in [fd_low, fd_high), ignoring errors.
confstr(name, /)
Return a string-valued system configuration variable.
cpu_count()
Return the number of CPUs in the system; return None if indeterminable.
ctermid()
Return the name of the controlling terminal for this process.
device_encoding(fd)
Return a string describing the encoding of a terminal's file descriptor.
The file descriptor must be attached to a terminal.
If the device is not a terminal, return None.
dup(fd, /)
Return a duplicate of a file descriptor.
dup2(fd, fd2, inheritable=True)
Duplicate file descriptor.
execl(file, *args)
execl(file, *args)
Execute the executable file with argument list args, replacing the
current process.
execle(file, *args)
execle(file, *args, env)
Execute the executable file with argument list args and
environment env, replacing the current process.
execlp(file, *args)
execlp(file, *args)
Execute the executable file (which is searched for along $PATH)
with argument list args, replacing the current process.
execlpe(file, *args)
execlpe(file, *args, env)
Execute the executable file (which is searched for along $PATH)
with argument list args and environment env, replacing the current
process.
execv(path, argv, /)
Execute an executable path with arguments, replacing current process.
path
Path of executable file.
argv
Tuple or list of strings.
execve(path, argv, env)
Execute an executable path with arguments, replacing current process.
path
Path of executable file.
argv
Tuple or list of strings.
env
Dictionary of strings mapping to strings.
execvp(file, args)
execvp(file, args)
Execute the executable file (which is searched for along $PATH)
with argument list args, replacing the current process.
args may be a list or tuple of strings.
execvpe(file, args, env)
execvpe(file, args, env)
Execute the executable file (which is searched for along $PATH)
with argument list args and environment env , replacing the
current process.
args may be a list or tuple of strings.
fchdir(fd)
Change to the directory of the given file descriptor.
fd must be opened on a directory, not a file.
Equivalent to os.chdir(fd).
fchmod(fd, mode)
Change the access permissions of the file given by file descriptor fd.
Equivalent to os.chmod(fd, mode).
fchown(fd, uid, gid)
Change the owner and group id of the file specified by file descriptor.
Equivalent to os.chown(fd, uid, gid).
fdatasync(fd)
Force write of fd to disk without forcing update of metadata.
fdopen(fd, *args, **kwargs)
# Supply os.fdopen()
fork()
Fork a child process.
Return 0 to child process and PID of child to parent process.
forkpty()
Fork a new process with a new pseudo-terminal as controlling tty.
Returns a tuple of (pid, master_fd).
Like fork(), return pid of 0 to the child process,
and pid of child to the parent process.
To both, return fd of newly opened pseudo-terminal.
fpathconf(fd, name, /)
Return the configuration limit name for the file descriptor fd.
If there is no limit, return -1.
fsdecode(filename)
Decode filename from the filesystem encoding with 'surrogateescape' error
handler, return str unchanged. On Windows, use 'strict' error handler if
the file system encoding is 'mbcs' (which is the default encoding).
fsencode(filename)
Encode filename to the filesystem encoding with 'surrogateescape' error
handler, return bytes unchanged. On Windows, use 'strict' error handler if
the file system encoding is 'mbcs' (which is the default encoding).
fstat(fd)
Perform a stat system call on the given file descriptor.
Like stat(), but for an open file descriptor.
Equivalent to os.stat(fd).
fstatvfs(fd, /)
Perform an fstatvfs system call on the given fd.
Equivalent to statvfs(fd).
fsync(fd)
Force write of fd to disk.
ftruncate(fd, length, /)
Truncate a file, specified by file descriptor, to a specific length.
fwalk(top='.', topdown=True, onerror=None, *, follow_symlinks=False, dir_fd=None)
Directory tree generator.
This behaves exactly like walk(), except that it yields a 4-tuple
dirpath, dirnames, filenames, dirfd
`dirpath`, `dirnames` and `filenames` are identical to walk() output,
and `dirfd` is a file descriptor referring to the directory `dirpath`.
The advantage of fwalk() over walk() is that it's safe against symlink
races (when follow_symlinks is False).
If dir_fd is not None, it should be a file descriptor open to a directory,
and top should be relative; top will then be relative to that directory.
(dir_fd is always supported for fwalk.)
Caution:
Since fwalk() yields file descriptors, those are only valid until the
next iteration step, so you should dup() them if you want to keep them
for a longer period.
Example:
import os
for root, dirs, files, rootfd in os.fwalk('python/Lib/email'):
print(root, "consumes", end="")
print(sum([os.stat(name, dir_fd=rootfd).st_size for name in files]),
end="")
print("bytes in", len(files), "non-directory files")
if 'CVS' in dirs:
dirs.remove('CVS') # don't visit CVS directories
get_blocking(...)
get_blocking(fd) -> bool
Get the blocking mode of the file descriptor:
False if the O_NONBLOCK flag is set, True if the flag is cleared.
get_exec_path(env=None)
Returns the sequence of directories that will be searched for the
named executable (similar to a shell) when launching a process.
*env* must be an environment variable dict or None. If *env* is None,
os.environ will be used.
get_inheritable(fd, /)
Get the close-on-exe flag of the specified file descriptor.
get_terminal_size(...)
Return the size of the terminal window as (columns, lines).
The optional argument fd (default standard output) specifies
which file descriptor should be queried.
If the file descriptor is not connected to a terminal, an OSError
is thrown.
This function will only be defined if an implementation is
available for this system.
shutil.get_terminal_size is the high-level function which should
normally be used, os.get_terminal_size is the low-level implementation.
getcwd()
Return a unicode string representing the current working directory.
getcwdb()
Return a bytes string representing the current working directory.
getegid()
Return the current process's effective group id.
getenv(key, default=None)
Get an environment variable, return None if it doesn't exist.
The optional second argument can specify an alternate default.
key, default and the result are str.
getenvb(key, default=None)
Get an environment variable, return None if it doesn't exist.
The optional second argument can specify an alternate default.
key, default and the result are bytes.
geteuid()
Return the current process's effective user id.
getgid()
Return the current process's group id.
getgrouplist(...)
getgrouplist(user, group) -> list of groups to which a user belongs
Returns a list of groups to which a user belongs.
user: username to lookup
group: base group id of the user
getgroups()
Return list of supplemental group IDs for the process.
getloadavg()
Return average recent system load information.
Return the number of processes in the system run queue averaged over
the last 1, 5, and 15 minutes as a tuple of three floats.
Raises OSError if the load average was unobtainable.
getlogin()
Return the actual login name.
getpgid(pid)
Call the system call getpgid(), and return the result.
getpgrp()
Return the current process group id.
getpid()
Return the current process id.
getppid()
Return the parent's process id.
If the parent process has already exited, Windows machines will still
return its id; others systems will return the id of the 'init' process (1).
getpriority(which, who)
Return program scheduling priority.
getresgid()
Return a tuple of the current process's real, effective, and saved group ids.
getresuid()
Return a tuple of the current process's real, effective, and saved user ids.
getsid(pid, /)
Call the system call getsid(pid) and return the result.
getuid()
Return the current process's user id.
getxattr(path, attribute, *, follow_symlinks=True)
Return the value of extended attribute attribute on path.
path may be either a string or an open file descriptor.
If follow_symlinks is False, and the last element of the path is a symbolic
link, getxattr will examine the symbolic link itself instead of the file
the link points to.
initgroups(...)
initgroups(username, gid) -> None
Call the system initgroups() to initialize the group access list with all of
the groups of which the specified username is a member, plus the specified
group id.
isatty(fd, /)
Return True if the fd is connected to a terminal.
Return True if the file descriptor is an open file descriptor
connected to the slave end of a terminal.
kill(pid, signal, /)
Kill a process with a signal.
killpg(pgid, signal, /)
Kill a process group with a signal.
lchown(path, uid, gid)
Change the owner and group id of path to the numeric uid and gid.
This function will not follow symbolic links.
Equivalent to os.chown(path, uid, gid, follow_symlinks=False).
link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True)
Create a hard link to a file.
If either src_dir_fd or dst_dir_fd is not None, it should be a file
descriptor open to a directory, and the respective path string (src or dst)
should be relative; the path will then be relative to that directory.
If follow_symlinks is False, and the last element of src is a symbolic
link, link will create a link to the symbolic link itself instead of the
file the link points to.
src_dir_fd, dst_dir_fd, and follow_symlinks may not be implemented on your
platform. If they are unavailable, using them will raise a
NotImplementedError.
listdir(path=None)
Return a list containing the names of the files in the directory.
path can be specified as either str or bytes. If path is bytes,
the filenames returned will also be bytes; in all other circumstances
the filenames returned will be str.
If path is None, uses the path='.'.
On some platforms, path may also be specified as an open file descriptor;\
the file descriptor must refer to a directory.
If this functionality is unavailable, using it raises NotImplementedError.
The list is in arbitrary order. It does not include the special
entries '.' and '..' even if they are present in the directory.
listxattr(path=None, *, follow_symlinks=True)
Return a list of extended attributes on path.
path may be either None, a string, or an open file descriptor.
if path is None, listxattr will examine the current directory.
If follow_symlinks is False, and the last element of the path is a symbolic
link, listxattr will examine the symbolic link itself instead of the file
the link points to.
lockf(fd, command, length, /)
Apply, test or remove a POSIX lock on an open file descriptor.
fd
An open file descriptor.
command
One of F_LOCK, F_TLOCK, F_ULOCK or F_TEST.
length
The number of bytes to lock, starting at the current position.
lseek(fd, position, how, /)
Set the position of a file descriptor. Return the new position.
Return the new cursor position in number of bytes
relative to the beginning of the file.
lstat(path, *, dir_fd=None)
Perform a stat system call on the given path, without following symbolic links.
Like stat(), but do not follow symbolic links.
Equivalent to stat(path, follow_symlinks=False).
major(device, /)
Extracts a device major number from a raw device number.
makedev(major, minor, /)
Composes a raw device number from the major and minor device numbers.
makedirs(name, mode=511, exist_ok=False)
makedirs(name [, mode=0o777][, exist_ok=False])
Super-mkdir; create a leaf directory and all intermediate ones. Works like
mkdir, except that any intermediate path segment (not just the rightmost)
will be created if it does not exist. If the target directory already
exists, raise an OSError if exist_ok is False. Otherwise no exception is
raised. This is recursive.
minor(device, /)
Extracts a device minor number from a raw device number.
mkdir(path, mode=511, *, dir_fd=None)
Create a directory.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
The mode argument is ignored on Windows.
mkfifo(path, mode=438, *, dir_fd=None)
Create a "fifo" (a POSIX named pipe).
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
mknod(path, mode=384, device=0, *, dir_fd=None)
Create a node in the file system.
Create a node in the file system (file, device special file or named pipe)
at path. mode specifies both the permissions to use and the
type of node to be created, being combined (bitwise OR) with one of
S_IFREG, S_IFCHR, S_IFBLK, and S_IFIFO. If S_IFCHR or S_IFBLK is set on mode,
device defines the newly created device special file (probably using
os.makedev()). Otherwise device is ignored.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
nice(increment, /)
Add increment to the priority of process and return the new priority.
open(path, flags, mode=511, *, dir_fd=None)
Open a file for low level IO. Returns a file descriptor (integer).
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
openpty()
Open a pseudo-terminal.
Return a tuple of (master_fd, slave_fd) containing open file descriptors
for both the master and slave ends.
pathconf(path, name)
Return the configuration limit name for the file or directory path.
If there is no limit, return -1.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
pipe()
Create a pipe.
Returns a tuple of two file descriptors:
(read_fd, write_fd)
pipe2(flags, /)
Create a pipe with flags set atomically.
Returns a tuple of two file descriptors:
(read_fd, write_fd)
flags can be constructed by ORing together one or more of these values:
O_NONBLOCK, O_CLOEXEC.
popen(cmd, mode='r', buffering=-1)
# Supply os.popen()
posix_fadvise(fd, offset, length, advice, /)
Announce an intention to access data in a specific pattern.
Announce an intention to access data in a specific pattern, thus allowing
the kernel to make optimizations.
The advice applies to the region of the file specified by fd starting at
offset and continuing for length bytes.
advice is one of POSIX_FADV_NORMAL, POSIX_FADV_SEQUENTIAL,
POSIX_FADV_RANDOM, POSIX_FADV_NOREUSE, POSIX_FADV_WILLNEED, or
POSIX_FADV_DONTNEED.
posix_fallocate(fd, offset, length, /)
Ensure a file has allocated at least a particular number of bytes on disk.
Ensure that the file specified by fd encompasses a range of bytes
starting at offset bytes from the beginning and continuing for length bytes.
pread(fd, length, offset, /)
Read a number of bytes from a file descriptor starting at a particular offset.
Read length bytes from file descriptor fd, starting at offset bytes from
the beginning of the file. The file offset remains unchanged.
putenv(name, value, /)
Change or add an environment variable.
pwrite(fd, buffer, offset, /)
Write bytes to a file descriptor starting at a particular offset.
Write buffer to fd, starting at offset bytes from the beginning of
the file. Returns the number of bytes writte. Does not change the
current file offset.
read(fd, length, /)
Read from a file descriptor. Returns a bytes object.
readlink(...)
readlink(path, *, dir_fd=None) -> path
Return a string representing the path to which the symbolic link points.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
readv(fd, buffers, /)
Read from a file descriptor fd into an iterable of buffers.
The buffers should be mutable buffers accepting bytes.
readv will transfer data into each buffer until it is full
and then move on to the next buffer in the sequence to hold
the rest of the data.
readv returns the total number of bytes read,
which may be less than the total capacity of all the buffers.
remove(path, *, dir_fd=None)
Remove a file (same as unlink()).
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
removedirs(name)
removedirs(name)
Super-rmdir; remove a leaf directory and all empty intermediate
ones. Works like rmdir except that, if the leaf directory is
successfully removed, directories corresponding to rightmost path
segments will be pruned away until either the whole path is
consumed or an error occurs. Errors during this latter phase are
ignored -- they generally mean that a directory was not empty.
removexattr(path, attribute, *, follow_symlinks=True)
Remove extended attribute attribute on path.
path may be either a string or an open file descriptor.
If follow_symlinks is False, and the last element of the path is a symbolic
link, removexattr will modify the symbolic link itself instead of the file
the link points to.
rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
Rename a file or directory.
If either src_dir_fd or dst_dir_fd is not None, it should be a file
descriptor open to a directory, and the respective path string (src or dst)
should be relative; the path will then be relative to that directory.
src_dir_fd and dst_dir_fd, may not be implemented on your platform.
If they are unavailable, using them will raise a NotImplementedError.
renames(old, new)
renames(old, new)
Super-rename; create directories as necessary and delete any left
empty. Works like rename, except creation of any intermediate
directories needed to make the new pathname good is attempted
first. After the rename, directories corresponding to rightmost
path segments of the old name will be pruned until either the
whole path is consumed or a nonempty directory is found.
Note: this function can fail with the new directory structure made
if you lack permissions needed to unlink the leaf directory or
file.
replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
Rename a file or directory, overwriting the destination.
If either src_dir_fd or dst_dir_fd is not None, it should be a file
descriptor open to a directory, and the respective path string (src or dst)
should be relative; the path will then be relative to that directory.
src_dir_fd and dst_dir_fd, may not be implemented on your platform.
If they are unavailable, using them will raise a NotImplementedError."
rmdir(path, *, dir_fd=None)
Remove a directory.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
scandir(...)
scandir(path='.') -> iterator of DirEntry objects for given path
sched_get_priority_max(policy)
Get the maximum scheduling priority for policy.
sched_get_priority_min(policy)
Get the minimum scheduling priority for policy.
sched_getaffinity(pid, /)
Return the affinity of the process identified by pid.
The affinity is returned as a set of CPU identifiers.
sched_getparam(pid, /)
Returns scheduling parameters for the process identified by pid.
If pid is 0, returns parameters for the calling process.
Return value is an instance of sched_param.
sched_getscheduler(pid, /)
Get the scheduling policy for the process identifiedy by pid.
Passing 0 for pid returns the scheduling policy for the calling process.
sched_rr_get_interval(pid, /)
Return the round-robin quantum for the process identified by pid, in seconds.
Value returned is a float.
sched_setaffinity(pid, mask, /)
Set the CPU affinity of the process identified by pid to mask.
mask should be an iterable of integers identifying CPUs.
sched_setparam(pid, param, /)
Set scheduling parameters for the process identified by pid.
If pid is 0, sets parameters for the calling process.
param should be an instance of sched_param.
sched_setscheduler(pid, policy, param, /)
Set the scheduling policy for the process identified by pid.
If pid is 0, the calling process is changed.
param is an instance of sched_param.
sched_yield()
Voluntarily relinquish the CPU.
sendfile(...)
sendfile(out, in, offset, count) -> byteswritten
sendfile(out, in, offset, count[, headers][, trailers], flags=0)
-> byteswritten
Copy count bytes from file descriptor in to file descriptor out.
set_blocking(...)
set_blocking(fd, blocking)
Set the blocking mode of the specified file descriptor.
Set the O_NONBLOCK flag if blocking is False,
clear the O_NONBLOCK flag otherwise.
set_inheritable(fd, inheritable, /)
Set the inheritable flag of the specified file descriptor.
setegid(egid, /)
Set the current process's effective group id.
seteuid(euid, /)
Set the current process's effective user id.
setgid(gid, /)
Set the current process's group id.
setgroups(groups, /)
Set the groups of the current process to list.
setpgid(pid, pgrp, /)
Call the system call setpgid(pid, pgrp).
setpgrp()
Make the current process the leader of its process group.
setpriority(which, who, priority)
Set program scheduling priority.
setregid(rgid, egid, /)
Set the current process's real and effective group ids.
setresgid(rgid, egid, sgid, /)
Set the current process's real, effective, and saved group ids.
setresuid(ruid, euid, suid, /)
Set the current process's real, effective, and saved user ids.
setreuid(ruid, euid, /)
Set the current process's real and effective user ids.
setsid()
Call the system call setsid().
setuid(uid, /)
Set the current process's user id.
setxattr(path, attribute, value, flags=0, *, follow_symlinks=True)
Set extended attribute attribute on path to value.
path may be either a string or an open file descriptor.
If follow_symlinks is False, and the last element of the path is a symbolic
link, setxattr will modify the symbolic link itself instead of the file
the link points to.
spawnl(mode, file, *args)
spawnl(mode, file, *args) -> integer
Execute file with arguments from args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnle(mode, file, *args)
spawnle(mode, file, *args, env) -> integer
Execute file with arguments from args in a subprocess with the
supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnlp(mode, file, *args)
spawnlp(mode, file, *args) -> integer
Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnlpe(mode, file, *args)
spawnlpe(mode, file, *args, env) -> integer
Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnv(mode, file, args)
spawnv(mode, file, args) -> integer
Execute file with arguments from args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnve(mode, file, args, env)
spawnve(mode, file, args, env) -> integer
Execute file with arguments from args in a subprocess with the
specified environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnvp(mode, file, args)
spawnvp(mode, file, args) -> integer
Execute file (which is looked for along $PATH) with arguments from
args in a subprocess.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
spawnvpe(mode, file, args, env)
spawnvpe(mode, file, args, env) -> integer
Execute file (which is looked for along $PATH) with arguments from
args in a subprocess with the supplied environment.
If mode == P_NOWAIT return the pid of the process.
If mode == P_WAIT return the process's exit code if it exits normally;
otherwise return -SIG, where SIG is the signal that killed it.
stat(path, *, dir_fd=None, follow_symlinks=True)
Perform a stat system call on the given path.
path
Path to be examined; can be string, bytes, or open-file-descriptor int.
dir_fd
If not None, it should be a file descriptor open to a directory,
and path should be a relative string; path will then be relative to
that directory.
follow_symlinks
If False, and the last element of the path is a symbolic link,
stat will examine the symbolic link itself instead of the file
the link points to.
dir_fd and follow_symlinks may not be implemented
on your platform. If they are unavailable, using them will raise a
NotImplementedError.
It's an error to use dir_fd or follow_symlinks when specifying path as
an open file descriptor.
stat_float_times(...)
stat_float_times([newval]) -> oldval
Determine whether os.[lf]stat represents time stamps as float objects.
If value is True, future calls to stat() return floats; if it is False,
future calls return ints.
If value is omitted, return the current setting.
statvfs(path)
Perform a statvfs system call on the given path.
path may always be specified as a string.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
strerror(code, /)
Translate an error code to a message string.
symlink(src, dst, target_is_directory=False, *, dir_fd=None)
Create a symbolic link pointing to src named dst.
target_is_directory is required on Windows if the target is to be
interpreted as a directory. (On Windows, symlink requires
Windows 6.0 or greater, and raises a NotImplementedError otherwise.)
target_is_directory is ignored on non-Windows platforms.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
sync()
Force write of everything to disk.
sysconf(name, /)
Return an integer-valued system configuration variable.
system(command)
Execute the command in a subshell.
tcgetpgrp(fd, /)
Return the process group associated with the terminal specified by fd.
tcsetpgrp(fd, pgid, /)
Set the process group associated with the terminal specified by fd.
times()
Return a collection containing process timing information.
The object returned behaves like a named tuple with these fields:
(utime, stime, cutime, cstime, elapsed_time)
All fields are floating point numbers.
truncate(path, length)
Truncate a file, specified by path, to a specific length.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
ttyname(fd, /)
Return the name of the terminal device connected to 'fd'.
fd
Integer file descriptor handle.
umask(mask, /)
Set the current numeric umask and return the previous umask.
uname()
Return an object identifying the current operating system.
The object behaves like a named tuple with the following fields:
(sysname, nodename, release, version, machine)
unlink(path, *, dir_fd=None)
Remove a file (same as remove()).
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
dir_fd may not be implemented on your platform.
If it is unavailable, using it will raise a NotImplementedError.
unsetenv(name, /)
Delete an environment variable.
urandom(size, /)
Return a bytes object containing random bytes suitable for cryptographic use.
utime(path, times=None, *, ns=None, dir_fd=None, follow_symlinks=True)
Set the access and modified time of path.
path may always be specified as a string.
On some platforms, path may also be specified as an open file descriptor.
If this functionality is unavailable, using it raises an exception.
If times is not None, it must be a tuple (atime, mtime);
atime and mtime should be expressed as float seconds since the epoch.
If ns is specified, it must be a tuple (atime_ns, mtime_ns);
atime_ns and mtime_ns should be expressed as integer nanoseconds
since the epoch.
If times is None and ns is unspecified, utime uses the current time.
Specifying tuples for both times and ns is an error.
If dir_fd is not None, it should be a file descriptor open to a directory,
and path should be relative; path will then be relative to that directory.
If follow_symlinks is False, and the last element of the path is a symbolic
link, utime will modify the symbolic link itself instead of the file the
link points to.
It is an error to use dir_fd or follow_symlinks when specifying path
as an open file descriptor.
dir_fd and follow_symlinks may not be available on your platform.
If they are unavailable, using them will raise a NotImplementedError.
wait()
Wait for completion of a child process.
Returns a tuple of information about the child process:
(pid, status)
wait3(options)
Wait for completion of a child process.
Returns a tuple of information about the child process:
(pid, status, rusage)
wait4(pid, options)
Wait for completion of a specific child process.
Returns a tuple of information about the child process:
(pid, status, rusage)
waitid(idtype, id, options, /)
Returns the result of waiting for a process or processes.
idtype
Must be one of be P_PID, P_PGID or P_ALL.
id
The id to wait on.
options
Constructed from the ORing of one or more of WEXITED, WSTOPPED
or WCONTINUED and additionally may be ORed with WNOHANG or WNOWAIT.
Returns either waitid_result or None if WNOHANG is specified and there are
no children in a waitable state.
waitpid(pid, options, /)
Wait for completion of a given child process.
Returns a tuple of information regarding the child process:
(pid, status)
The options argument is ignored on Windows.
walk(top, topdown=True, onerror=None, followlinks=False)
Directory tree generator.
For each directory in the directory tree rooted at top (including top
itself, but excluding '.' and '..'), yields a 3-tuple
dirpath, dirnames, filenames
dirpath is a string, the path to the directory. dirnames is a list of
the names of the subdirectories in dirpath (excluding '.' and '..').
filenames is a list of the names of the non-directory files in dirpath.
Note that the names in the lists are just names, with no path components.
To get a full path (which begins with top) to a file or directory in
dirpath, do os.path.join(dirpath, name).
If optional arg 'topdown' is true or not specified, the triple for a
directory is generated before the triples for any of its subdirectories
(directories are generated top down). If topdown is false, the triple
for a directory is generated after the triples for all of its
subdirectories (directories are generated bottom up).
When topdown is true, the caller can modify the dirnames list in-place
(e.g., via del or slice assignment), and walk will only recurse into the
subdirectories whose names remain in dirnames; this can be used to prune the
search, or to impose a specific order of visiting. Modifying dirnames when
topdown is false is ineffective, since the directories in dirnames have
already been generated by the time dirnames itself is generated. No matter
the value of topdown, the list of subdirectories is retrieved before the
tuples for the directory and its subdirectories are generated.
By default errors from the os.scandir() call are ignored. If
optional arg 'onerror' is specified, it should be a function; it
will be called with one argument, an OSError instance. It can
report the error to continue with the walk, or raise the exception
to abort the walk. Note that the filename is available as the
filename attribute of the exception object.
By default, os.walk does not follow symbolic links to subdirectories on
systems that support them. In order to get this functionality, set the
optional argument 'followlinks' to true.
Caution: if you pass a relative pathname for top, don't change the
current working directory between resumptions of walk. walk never
changes the current directory, and assumes that the client doesn't
either.
Example:
import os
from os.path import join, getsize
for root, dirs, files in os.walk('python/Lib/email'):
print(root, "consumes", end="")
print(sum([getsize(join(root, name)) for name in files]), end="")
print("bytes in", len(files), "non-directory files")
if 'CVS' in dirs:
dirs.remove('CVS') # don't visit CVS directories
write(fd, data, /)
Write a bytes object to a file descriptor.
writev(fd, buffers, /)
Iterate over buffers, and write the contents of each to a file descriptor.
Returns the total number of bytes written.
buffers must be a sequence of bytes-like objects.
DATA
CLD_CONTINUED = 6
CLD_DUMPED = 3
CLD_EXITED = 1
CLD_TRAPPED = 4
EX_CANTCREAT = 73
EX_CONFIG = 78
EX_DATAERR = 65
EX_IOERR = 74
EX_NOHOST = 68
EX_NOINPUT = 66
EX_NOPERM = 77
EX_NOUSER = 67
EX_OK = 0
EX_OSERR = 71
EX_OSFILE = 72
EX_PROTOCOL = 76
EX_SOFTWARE = 70
EX_TEMPFAIL = 75
EX_UNAVAILABLE = 69
EX_USAGE = 64
F_LOCK = 1
F_OK = 0
F_TEST = 3
F_TLOCK = 2
F_ULOCK = 0
NGROUPS_MAX = 65536
O_ACCMODE = 3
O_APPEND = 1024
O_ASYNC = 8192
O_CLOEXEC = 524288
O_CREAT = 64
O_DIRECT = 16384
O_DIRECTORY = 65536
O_DSYNC = 4096
O_EXCL = 128
O_LARGEFILE = 0
O_NDELAY = 2048
O_NOATIME = 262144
O_NOCTTY = 256
O_NOFOLLOW = 131072
O_NONBLOCK = 2048
O_PATH = 2097152
O_RDONLY = 0
O_RDWR = 2
O_RSYNC = 1052672
O_SYNC = 1052672
O_TMPFILE = 4259840
O_TRUNC = 512
O_WRONLY = 1
POSIX_FADV_DONTNEED = 4
POSIX_FADV_NOREUSE = 5
POSIX_FADV_NORMAL = 0
POSIX_FADV_RANDOM = 1
POSIX_FADV_SEQUENTIAL = 2
POSIX_FADV_WILLNEED = 3
PRIO_PGRP = 1
PRIO_PROCESS = 0
PRIO_USER = 2
P_ALL = 0
P_NOWAIT = 1
P_NOWAITO = 1
P_PGID = 2
P_PID = 1
P_WAIT = 0
RTLD_DEEPBIND = 8
RTLD_GLOBAL = 256
RTLD_LAZY = 1
RTLD_LOCAL = 0
RTLD_NODELETE = 4096
RTLD_NOLOAD = 4
RTLD_NOW = 2
R_OK = 4
SCHED_BATCH = 3
SCHED_FIFO = 1
SCHED_IDLE = 5
SCHED_OTHER = 0
SCHED_RESET_ON_FORK = 1073741824
SCHED_RR = 2
SEEK_CUR = 1
SEEK_DATA = 3
SEEK_END = 2
SEEK_HOLE = 4
SEEK_SET = 0
ST_APPEND = 256
ST_MANDLOCK = 64
ST_NOATIME = 1024
ST_NODEV = 4
ST_NODIRATIME = 2048
ST_NOEXEC = 8
ST_NOSUID = 2
ST_RDONLY = 1
ST_RELATIME = 4096
ST_SYNCHRONOUS = 16
ST_WRITE = 128
TMP_MAX = 238328
WCONTINUED = 8
WEXITED = 4
WNOHANG = 1
WNOWAIT = 16777216
WSTOPPED = 2
WUNTRACED = 2
W_OK = 2
XATTR_CREATE = 1
XATTR_REPLACE = 2
XATTR_SIZE_MAX = 65536
X_OK = 1
__all__ = ['altsep', 'curdir', 'pardir', 'sep', 'pathsep', 'linesep', ...
altsep = None
confstr_names = {'CS_GNU_LIBC_VERSION': 2, 'CS_GNU_LIBPTHREAD_VERSION'...
curdir = '.'
defpath = ':/bin:/usr/bin'
devnull = '/dev/null'
environ = environ({'VIRTUAL_ENV': '/home/hobs/.virtualenvs...XDG_SESSI...
environb = environ({b'VIRTUAL_ENV': b'/home/hobs/.virtualen..._SESSION...
extsep = '.'
linesep = '\n'
name = 'posix'
pardir = '..'
pathconf_names = {'PC_ALLOC_SIZE_MIN': 18, 'PC_ASYNC_IO': 10, 'PC_CHOW...
pathsep = ':'
sep = '/'
supports_bytes_environ = True
sysconf_names = {'SC_2_CHAR_TERM': 95, 'SC_2_C_BIND': 47, 'SC_2_C_DEV'...
FILE
/home/hobs/.virtualenvs/civicu/lib/python3.5/os.py
In [13]:
print(os.environ)
environ({'VIRTUAL_ENV': '/home/hobs/.virtualenvs/civicu', 'OLDPWD': '/home/hobs', 'MANDATORY_PATH': '/usr/share/gconf/ubuntu.mandatory.path', 'SSH_AUTH_SOCK': '/run/user/1000/keyring/ssh', 'GTK_IM_MODULE': 'ibus', '_': '/home/hobs/.virtualenvs/civicu/bin/jupyter', 'XDG_GREETER_DATA_DIR': '/var/lib/lightdm-data/hobs', 'PAGER': 'cat', 'XAUTHORITY': '/home/hobs/.Xauthority', 'HISTORY_PATH': '/home/hobs/.bash_history_forever', 'HOME': '/home/hobs', 'QT_ACCESSIBILITY': '1', 'GNUPLOT_DEFAULT_GDFONT': 'DejaVuSans.ttf', 'EDITOR': 'nano', 'JOURNAL_STREAM': '8:29472', 'COMPIZ_BIN_PATH': '/usr/bin/', 'LESSCLOSE': '/usr/bin/lesspipe %s %s', 'QT_LINUX_ACCESSIBILITY_ALWAYS_ON': '1', 'TERM': 'xterm-color', 'XDG_SEAT_PATH': '/org/freedesktop/DisplayManager/Seat0', 'SHLVL': '2', 'QT4_IM_MODULE': 'xim', 'LANGUAGE': 'en_US', 'GDFONTPATH': '/usr/share/fonts/truetype/ttf-dejavu', 'EC2_HOME': '/usr/local/ec2-api-tools', 'PATH': '/home/hobs/.virtualenvs/civicu/bin:/home/hobs/.virtualenvs/civicu/bin:.:/usr/local/bin/:/home/hobs/bin:/home/hobs/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin', 'WORKON_HOME': '/home/hobs/.virtualenvs', 'XDG_SESSION_PATH': '/org/freedesktop/DisplayManager/Session0', 'VIRTUALENVWRAPPER_PROJECT_FILENAME': '.project', 'CLICOLOR': '1', 'MPLBACKEND': 'module://ipykernel.pylab.backend_inline', 'SESSION_MANAGER': 'local/spectre:@/tmp/.ICE-unix/1805,unix/spectre:/tmp/.ICE-unix/1805', 'GTK2_MODULES': 'overlay-scrollbar', 'XDG_DATA_DIRS': '/usr/share/ubuntu:/usr/local/share/:/usr/share/:/var/lib/snapd/desktop', 'JPY_PARENT_PID': '17683', 'COLORTERM': 'truecolor', 'USER': 'hobs', 'XDG_SESSION_DESKTOP': 'ubuntu', 'GDM_LANG': 'en_US', 'XDG_CONFIG_DIRS': '/etc/xdg/xdg-ubuntu:/etc/xdg', 'GNOME_DESKTOP_SESSION_ID': 'this-is-deprecated', 'SHELL': '/bin/bash', 'EB_HOME': '/usr/local/AWS-ElasticBeanstalk-CLI', 'COMPIZ_CONFIG_PROFILE': 'ubuntu', 'XDG_CURRENT_DESKTOP': 'Unity:Unity7', 'VIRTUALENVWRAPPER_SCRIPT': '/usr/local/bin/virtualenvwrapper.sh', 'INVOCATION_ID': 'e83e8bbe87234a0e82a0cab937fad320', 'PROMPT_COMMAND': 'DATETIMESTAMP=$(history 1 | cut -c -27); echo "${DATETIMESTAMP}# cd $PWD" >> $HISTORY_PATH; history -a; history -c; history -r; history 1 >> /home/hobs/.bash_history_forever; ', 'LOGNAME': 'hobs', 'CLUTTER_IM_MODULE': 'xim', 'PROJECT_HOME': '/home/hobs/src', 'IM_CONFIG_PHASE': '1', 'TOUCHSCREEN_DEVICE_ID': '12', 'VTE_VERSION': '4402', 'GDMSESSION': 'ubuntu', 'LESSOPEN': '| /usr/bin/lesspipe %s', 'DEFAULTS_PATH': '/usr/share/gconf/ubuntu.default.path', 'XMODIFIERS': '@im=ibus', 'GIT_PAGER': 'cat', 'MANAGERPID': '1480', 'PS1': '(civicu) ${debian_chroot:+($debian_chroot)}\\u@\\h:\\w/ \\[\\033[00;32m\\]$(parse_git_branch)\\[\\033[00m\\]\n$ ', 'GNOME_SESSION_XDG_SESSION_PATH': '/org/freedesktop/DisplayManager/Session0', 'PWD': '/home/hobs/src/civicu-pythonii-summer-2017', 'LS_COLORS': 'rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:', 'QT_IM_MODULE': 'ibus', 'XDG_RUNTIME_DIR': '/run/user/1000', 'SSH_AGENT_LAUNCHER': 'gnome-keyring', 'DESKTOP_SESSION': 'ubuntu', 'XDG_MENU_PREFIX': 'gnome-', 'DISPLAY': ':0', 'DBUS_SESSION_BUS_ADDRESS': 'unix:path=/run/user/1000/bus', 'GTK_MODULES': 'gail:atk-bridge:unity-gtk-module', 'WINDOWID': '69206022', 'VIRTUALENVWRAPPER_HOOK_DIR': '/home/hobs/.virtualenvs', 'VIRTUALENVWRAPPER_WORKON_CD': '1', 'XDG_SESSION_TYPE': 'x11', 'LANG': 'en_US.UTF-8'})
In [14]:
# os.environ is some sort of combination dictionary and environment object
# this is because it is "editable" so you can change your OS environment variables in python!
# but that means you have to get the environment variable names right
os.environ['USERNAME']
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
<ipython-input-14-9e0f0557e9d6> in <module>()
1 # os.environ is some sort of combination dictionary and environment object
2 # this is because it is "editable" so you can change your OS environment variables in python!
----> 3 os.environ['USERNAME']
~/.virtualenvs/civicu/lib/python3.5/os.py in __getitem__(self, key)
723 except KeyError:
724 # raise KeyError with the original key value
--> 725 raise KeyError(key) from None
726 return self.decodevalue(value)
727
KeyError: 'USERNAME'
In [21]:
# on dictionaries we can use the `get` method to avoid KeyError's
# `.get` also allows us to set a default value to be returned if the key doesn't exist
print(os.environ.get('USERNAME'))
None
In [22]:
print(os.environ.get('USERNAME', 'default'))
default
In [23]:
# there's also a convenience function in `os` if you just want to *READ* a variable on an unknown operating system
print(os.getenv('USERNAME'))
None
In [5]:
# Our bot would like to know who's logged into the computer
# Where can we access environment variables
print(sorted(os.environ.keys()))
['CLICOLOR', 'CLUTTER_IM_MODULE', 'COLORTERM', 'COMPIZ_BIN_PATH', 'COMPIZ_CONFIG_PROFILE', 'DBUS_SESSION_BUS_ADDRESS', 'DEFAULTS_PATH', 'DESKTOP_SESSION', 'DISPLAY', 'EB_HOME', 'EC2_HOME', 'EDITOR', 'GDFONTPATH', 'GDMSESSION', 'GDM_LANG', 'GIT_PAGER', 'GNOME_DESKTOP_SESSION_ID', 'GNOME_SESSION_XDG_SESSION_PATH', 'GNUPLOT_DEFAULT_GDFONT', 'GTK2_MODULES', 'GTK_IM_MODULE', 'GTK_MODULES', 'HISTORY_PATH', 'HOME', 'IM_CONFIG_PHASE', 'INVOCATION_ID', 'JOURNAL_STREAM', 'JPY_PARENT_PID', 'LANG', 'LANGUAGE', 'LESSCLOSE', 'LESSOPEN', 'LOGNAME', 'LS_COLORS', 'MANAGERPID', 'MANDATORY_PATH', 'MPLBACKEND', 'OLDPWD', 'PAGER', 'PATH', 'PROJECT_HOME', 'PROMPT_COMMAND', 'PS1', 'PWD', 'QT4_IM_MODULE', 'QT_ACCESSIBILITY', 'QT_IM_MODULE', 'QT_LINUX_ACCESSIBILITY_ALWAYS_ON', 'SESSION_MANAGER', 'SHELL', 'SHLVL', 'SSH_AGENT_LAUNCHER', 'SSH_AUTH_SOCK', 'TERM', 'TOUCHSCREEN_DEVICE_ID', 'USER', 'VIRTUALENVWRAPPER_HOOK_DIR', 'VIRTUALENVWRAPPER_PROJECT_FILENAME', 'VIRTUALENVWRAPPER_SCRIPT', 'VIRTUALENVWRAPPER_WORKON_CD', 'VIRTUAL_ENV', 'VTE_VERSION', 'WINDOWID', 'WORKON_HOME', 'XAUTHORITY', 'XDG_CONFIG_DIRS', 'XDG_CURRENT_DESKTOP', 'XDG_DATA_DIRS', 'XDG_GREETER_DATA_DIR', 'XDG_MENU_PREFIX', 'XDG_RUNTIME_DIR', 'XDG_SEAT_PATH', 'XDG_SESSION_DESKTOP', 'XDG_SESSION_PATH', 'XDG_SESSION_TYPE', 'XMODIFIERS', '_']
In [8]:
os.environ['USERNAME']
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
<ipython-input-8-cb8f1699ae7e> in <module>()
----> 1 os.environ['USERNAME']
~/.virtualenvs/civicu/lib/python3.5/os.py in __getitem__(self, key)
723 except KeyError:
724 # raise KeyError with the original key value
--> 725 raise KeyError(key) from None
726 return self.decodevalue(value)
727
KeyError: 'USERNAME'
In [7]:
# So we could look for the $USER variable
os.environ['USER']
Out[7]:
'hobs'
In [24]:
# we can also check multiple variations and use the first one that isn't None
os.getenv('USERNAME') or os.getenv('USER')
Out[24]:
'hobs'
In [ ]:
# do a [ctrl]-F on your user name to find it among some of your other environment variables
# notice that it is part of your HOME path?
os.path.basedir
Content source: developerQuinnZ/this_will_work
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