Strings are very easy to use in python.

There are four ways to write strings:



In [3]:

    
x = "Hello, Python!" # Enclosed in double quotes
print x









    



Hello, Python!



In [4]:

    
y = 'Hello, Python!' # Single quotes
print y









    



Hello, Python!



In [4]:

    
"""Hello, Python!""" # Triple quotes









    Out[4]:





'Hello, Python!'



In [5]:

    
'''Hello, Python!''' # Triple quotes can use single quotes as well !









    Out[5]:





'Hello, Python!'

As you can see, you get the same content in all three cases. Triple quotes allow entry of multi-line strings. Double-quote allows single quotes to be used freely inside the string. Using single quotes likewise allows double-quotes to be used in the string. Special characters need to be "escape"d, as in C.



In [2]:

    
'"And this too, shall pass"'









    Out[2]:





'"And this too, shall pass"'



In [3]:

    
"'And this too, shall pass'"









    Out[3]:





"'And this too, shall pass'"

Note that each string is actually a string object. This means that many operations are defined on the string.



In [9]:

    
s = "Hello, Python!"
dir(s)









    Out[9]:





['__add__',
 '__class__',
 '__contains__',
 '__delattr__',
 '__doc__',
 '__eq__',
 '__format__',
 '__ge__',
 '__getattribute__',
 '__getitem__',
 '__getnewargs__',
 '__getslice__',
 '__gt__',
 '__hash__',
 '__init__',
 '__le__',
 '__len__',
 '__lt__',
 '__mod__',
 '__mul__',
 '__ne__',
 '__new__',
 '__reduce__',
 '__reduce_ex__',
 '__repr__',
 '__rmod__',
 '__rmul__',
 '__setattr__',
 '__sizeof__',
 '__str__',
 '__subclasshook__',
 '_formatter_field_name_split',
 '_formatter_parser',
 'capitalize',
 'center',
 'count',
 'decode',
 'encode',
 'endswith',
 'expandtabs',
 'find',
 'format',
 'index',
 'isalnum',
 'isalpha',
 'isdigit',
 'islower',
 'isspace',
 'istitle',
 'isupper',
 'join',
 'ljust',
 'lower',
 'lstrip',
 'partition',
 'replace',
 'rfind',
 'rindex',
 'rjust',
 'rpartition',
 'rsplit',
 'rstrip',
 'split',
 'splitlines',
 'startswith',
 'strip',
 'swapcase',
 'title',
 'translate',
 'upper',
 'zfill']



In [10]:

    
s.upper()









    Out[10]:





'HELLO, PYTHON!'



In [11]:

    
s.lower()









    Out[11]:





'hello, python!'



In [13]:

    
s.split(', ')









    Out[13]:





['Hello', 'Python!']



In [14]:

    
s.startswith('Hello')









    Out[14]:





True



In [21]:

    
len(s) # number of chars









    Out[21]:





14

You may use the [] operator to extract parts of the string.



In [15]:

    
s[0]









    Out[15]:





'H'



In [17]:

    
s[0:2]









    Out[17]:





'He'



In [24]:

    
s[1:6]









    Out[24]:





'ello,'



In [18]:

    
s[-1] # last char









    Out[18]:





'!'



In [20]:

    
s[0:-2] # all but last char









    Out[20]:





'Hello, Pytho'