In [1]:

    

a = 1010
a, type(a)


    

    
Out[1]:





(1010, int)

In [2]:

    

a = 'Welcome to Python world!'
a, type(a)


    

    
Out[2]:





('Welcome to Python world!', str)

In [3]:

    

a = 3.14
a, type(a)


    

    
Out[3]:





(3.14, float)

In [4]:

    

a = 'x'
a, type(a)


    

    
Out[4]:





('x', str)

In [5]:

    

3.14 + 10


    

    
Out[5]:





13.14

In [6]:

    

'Hello' + ' ' + 'World'


    

    
Out[6]:





'Hello World'

In [7]:

    

#list
xs = [ 1, 2, 3, 4, 5 ]
xs


    

    
Out[7]:





[1, 2, 3, 4, 5]

In [8]:

    

for x in xs:
    print x


    

    




1
2
3
4
5

In [9]:

    

#tuple
ts = (1, 2, 3, 4, 5)
ts


    

    
Out[9]:





(1, 2, 3, 4, 5)

In [11]:

    

for t in ts:
    print t


    

    




1
2
3
4
5

In [12]:

    

a1, a2, a3, a4, a5 = ts
print a1, a2, a3, a4, a5


    

    




1 2 3 4 5

In [13]:

    

v1 = 123
v2 = 'aha'
print 'before swap:', v1, v2
v2, v1 = v1, v2
print "after swap:", v1, v2


    

    




before swap: 123 aha
after swap: aha 123

In [14]:

    

#slicing
xs[1:4]


    

    
Out[14]:





[2, 3, 4]

In [15]:

    

xs[1:]


    

    
Out[15]:





[2, 3, 4, 5]

In [16]:

    

xs[1:4:2]


    

    
Out[16]:





[2, 4]

In [17]:

    

xs[-1]


    

    
Out[17]:





5

In [18]:

    

xs[-2]


    

    
Out[18]:





4

In [19]:

    

xs[:2] + xs[-2:]


    

    
Out[19]:





[1, 2, 4, 5]

In [20]:

    

ts[::-1]


    

    
Out[20]:





(5, 4, 3, 2, 1)

In [21]:

    

s = "Python is awesome."
s[::-1]


    

    
Out[21]:





'.emosewa si nohtyP'

In [22]:

    

#dictionary
ds = { 10:'1', 20:'2', '3':30, '4':40 }
ds


    

    
Out[22]:





{10: '1', 20: '2', '3': 30, '4': 40}

In [23]:

    

ds.keys()


    

    
Out[23]:





[10, 20, '3', '4']

In [24]:

    

ds.values()


    

    
Out[24]:





['1', '2', 30, 40]

In [25]:

    

ds.items()


    

    
Out[25]:





[(10, '1'), (20, '2'), ('3', 30), ('4', 40)]

In [26]:

    

for idx,line in enumerate(file("big.txt")):
    if idx > 4:
        break
    print idx, line


    

    




0 The Project Gutenberg EBook of The Adventures of Sherlock Holmes

1 by Sir Arthur Conan Doyle

2 (#15 in our series by Sir Arthur Conan Doyle)

3 

4 Copyright laws are changing all over the world. Be sure to check the

In [27]:

    

evens = [ x for x in range(100) if x % 2 == 0 ]


    

In [28]:

    

evens[:5]


    

    
Out[28]:





[0, 2, 4, 6, 8]

In [29]:

    

even_squares = [ x**2 for x in range(100) if x % 2 == 0 ]


    

In [30]:

    

even_squares[:5]


    

    
Out[30]:





[0, 4, 16, 36, 64]

In [31]:

    

even_square_dict = dict( (x, x**2) for x in range(100) if x % 2 == 0 )


    

In [32]:

    

even_square_dict[8]


    

    
Out[32]:





64

In [33]:

    

even_square_dict[28]


    

    
Out[33]:





784