In [1]:

    

squares = []

for i in range(10):
    squares.append(i**2)

squares


    

    
Out[1]:





[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

In [2]:

    

squares = [i**2 for i in range(10)]


    

In [3]:

    

squares


    

    
Out[3]:





[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

In [4]:

    

squares3 = [i**2 for i in range(30) if i % 3 == 0]
squares3


    

    
Out[4]:





[0, 9, 36, 81, 144, 225, 324, 441, 576, 729]

In [5]:

    

squares3_dict = {i: i**2 for i in range(30) if i % 3 == 0}
squares3_dict


    

    
Out[5]:





{0: 0,
 3: 9,
 6: 36,
 9: 81,
 12: 144,
 15: 225,
 18: 324,
 21: 441,
 24: 576,
 27: 729}

In [6]:

    

capitals = {'United States': 'Washington, DC','France': 'Paris','Italy': 'Rome'}


    

In [7]:

    

capitals_bycapital = {capitals[key]: key for key in capitals}


    

In [8]:

    

capitals_bycapital


    

    
Out[8]:





{'Paris': 'France', 'Rome': 'Italy', 'Washington, DC': 'United States'}

In [9]:

    

sum([i**2 for i in range(10)])


    

    
Out[9]:





285

In [10]:

    

sum(i**2 for i in range(10))


    

    
Out[10]:





285

In [ ]: