Someone at the 2015-03-06 dojo had a question about the meaning of {0[0]} and {0[1]} in format strings for specifying arguments on page 224 of Learning Python, 5th edition. So we played with it below.



In [1]:

    
somelist = list('SPAM')
somelist









    Out[1]:





['S', 'P', 'A', 'M']



In [2]:

    
somelist[0]









    Out[2]:





'S'



In [3]:

    
somelist[2]









    Out[3]:





'A'



In [4]:

    
'first={0}, last={1}'.format(somelist[0], somelist[-1])









    Out[4]:





'first=S, last=M'



In [5]:

    
'first={0[0]}, third={0[2]}, another={1}'.format(somelist, 'hello')









    Out[5]:





'first=S, third=A, another=hello'



In [6]:

    
somedict = {'hello': 'world', 5: 3}
somedict









    Out[6]:





{'hello': 'world', 5: 3}



In [7]:

    
'first={0[hello]}, third={0[5]}, another={1}'.format(somedict, 'hello')









    Out[7]:





'first=world, third=3, another=hello'