In [3]:

    

s = 'Hello World!'


    

In [4]:

    

str(s)


    

    
Out[4]:





'Hello World!'

In [5]:

    

repr(s)


    

    
Out[5]:





"'Hello World!'"

In [6]:

    

str(1/7)


    

    
Out[6]:





'0.14285714285714285'

In [10]:

    

repr(1/7)


    

    
Out[10]:





'0.14285714285714285'

In [9]:

    

x = 10 * 3.25
y = 200 * 200
s = 'the value of x is ' + repr(x) + ', and y is ' + repr(y) + '...'
print(s)


    

    




the value of x is 32.5, and y is 40000...

In [12]:

    

hello = 'Hello, World\n'
hellos = repr(hello)
print(hellos)


    

    




'Hello, World\n'

In [13]:

    

repr((x,y,('spam','eggs')))


    

    
Out[13]:





"(32.5, 40000, ('spam', 'eggs'))"

In [17]:

    

for x in range(1, 11):
    print(repr(x).rjust(2), repr(x*x).rjust(3), end='')
    print(repr(x*x*x).rjust(4))


    

    




 1   1   1
 2   4   8
 3   9  27
 4  16  64
 5  25 125
 6  36 216
 7  49 343
 8  64 512
 9  81 729
10 1001000

In [2]:

    

for x in range(1,11):
    print('{0:2d} {1:3d} {2:4d}'.format(x,x*x,x*x*x))


    

    




 1   1    1
 2   4    8
 3   9   27
 4  16   64
 5  25  125
 6  36  216
 7  49  343
 8  64  512
 9  81  729
10 100 1000

In [3]:

    

'12'.zfill(5)


    

    
Out[3]:





'00012'

In [4]:

    

'-3.14'.zfill(7)


    

    
Out[4]:





'-003.14'

In [5]:

    

'3.14159280098'.zfill(5)


    

    
Out[5]:





'3.14159280098'

In [6]:

    

print('we are the {} who say"{}!"'.format('knight','ni'))


    

    




we are the knight who say"ni!"

In [7]:

    

print('{0} and {1}'.format('spam','eggs'))


    

    




spam and eggs

In [8]:

    

print('{1} and {0}'.format('spam','eggs'))


    

    




eggs and spam

In [9]:

    

print('this {food} is {adj}'.format(food = 'spam', adj = 'delicious'))


    

    




this spam is delicious

In [10]:

    

print('the story of {0},{1}, and {others}.'.format('bill','tom', others = 'gates'))


    

    




the story of bill,tom, and gates.

In [13]:

    

import math
print('the value of PI is {}'.format(math.pi))


    

    




the value of PI is 3.141592653589793

In [12]:

    

print('the value of PI is {!r}'.format(math.pi))


    

    




the value of PI is 3.141592653589793

In [14]:

    

print('the value of PI is {0:.3f}'.format(math.pi))


    

    




the value of PI is 3.142

In [27]:

    

table = {'Mike': 4113, 'Tom': 9918, 'Jack': 5098}
for name, phone in table.items():
    print('{0:10} ==> {1:10d}'.format(name, phone))


    

    




Tom        ==>       9918
Jack       ==>       5098
Mike       ==>       4113

In [28]:

    

table = {'Mike': 4413, 'Tom': 9918, 'Jack': 5098}
print('Mike:{0[Mike]:d}; Tom:{0[Tom]:d}; Jack:{0[Jack]:d}'.format(table))


    

    




Mike:4413; Tom:9918; Jack:5098

In [30]:

    

table = {'Mike': 4413, 'Tom': 9918, 'Jack': 5098}
print('Mike:{Mike:d}; Tom:{Tom:d}; Jack:{Jack:d}'.format(**table))


    

    




Mike:4413; Tom:9918; Jack:5098

In [41]:

    

f = open('f.py','r')


    

In [42]:

    

f.read()


    

    
Out[42]:





"def fib(n):    # write Fibonacci series up to n\n    a, b = 0, 1\n    while b < n:\n        print(b, end=' ')\n        a, b = b, a+b\n    print()\n\ndef fib2(n): # return Fibonacci series up to n\n    result = []\n    a, b = 0, 1\n    while b < n:\n        result.append(b)\n        a, b = b, a+b\n    return result\n"

In [43]:

    

f.readline()


    

    
Out[43]:





''

In [51]:

    

f = open('f.py','r')


    

In [52]:

    

f.readlines()


    

    
Out[52]:





['def fib(n):    # write Fibonacci series up to n\n',
 '    a, b = 0, 1\n',
 '    while b < n:\n',
 "        print(b, end=' ')\n",
 '        a, b = b, a+b\n',
 '    print()\n',
 '\n',
 'def fib2(n): # return Fibonacci series up to n\n',
 '    result = []\n',
 '    a, b = 0, 1\n',
 '    while b < n:\n',
 '        result.append(b)\n',
 '        a, b = b, a+b\n',
 '    return result\n']

In [50]:

    

list(f)


    

    
Out[50]:





['def fib(n):    # write Fibonacci series up to n\n',
 '    a, b = 0, 1\n',
 '    while b < n:\n',
 "        print(b, end=' ')\n",
 '        a, b = b, a+b\n',
 '    print()\n',
 '\n',
 'def fib2(n): # return Fibonacci series up to n\n',
 '    result = []\n',
 '    a, b = 0, 1\n',
 '    while b < n:\n',
 '        result.append(b)\n',
 '        a, b = b, a+b\n',
 '    return result\n']

In [47]:

    

for line in f:
    print(line, end='')


    

    




def fib(n):    # write Fibonacci series up to n
    a, b = 0, 1
    while b < n:
        print(b, end=' ')
        a, b = b, a+b
    print()

def fib2(n): # return Fibonacci series up to n
    result = []
    a, b = 0, 1
    while b < n:
        result.append(b)
        a, b = b, a+b
    return result

In [54]:

    

f.write('#this is a test')


    

    




---------------------------------------------------------------------------
UnsupportedOperation                      Traceback (most recent call last)
<ipython-input-54-bc0cdacc1b31> in <module>()
----> 1 f.write('#this is a test')

UnsupportedOperation: not writable

In [55]:

    

f = open('workfile', 'rb+')
f.write(b'0123456789abcdef')


    

    
Out[55]:





16

In [56]:

    

f.seek(7)


    

    
Out[56]:





7

In [57]:

    

f.read(1)


    

    
Out[57]:





b'7'

In [61]:

    

f.seek(13)


    

    
Out[61]:





13

In [62]:

    

with open('workfile', 'r') as f:
    read_data = f.read()
f.closed


    

    
Out[62]:





True