53 To access the last element, we can use -1 as the index! |
53 To access the last element, we can use -1 as the index! |
54 print a[-1] |
54 print a[-1] |
55 Similarly, we could access other elements with corresponding -ve |
55 Similarly, we could access other elements with corresponding -ve |
56 indexes. This is a very handy feature of python. |
56 indexes. This is a very handy feature of python. |
57 |
57 |
58 The len function, which we used with lists, works with strings too. |
58 The len function, which we used with lists and arrays, works with |
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59 strings too. |
59 len(a) |
60 len(a) |
60 |
61 |
61 Python's strings support the operations + and * |
62 Python's strings support the operations + and * |
62 a + b |
63 a + b |
63 a * 4 |
64 a * 4 |
92 Python also has a 'join' function, which does the opposite of what |
93 Python also has a 'join' function, which does the opposite of what |
93 split does. |
94 split does. |
94 ' '.join(alist) will return the original string a. |
95 ' '.join(alist) will return the original string a. |
95 '-'.join(alist) will return a string with the spaces in the string |
96 '-'.join(alist) will return a string with the spaces in the string |
96 'a' replaced with hyphens. |
97 'a' replaced with hyphens. |
97 |
98 |
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99 At times we want our output or message in a particular |
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100 format with variables embedded, something like printf in C. For |
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101 those situations python provides a provision. First lets create some |
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102 variables |
98 * formatting - printf style * |
103 * formatting - printf style * |
99 In []: x, y = 1, 1.234 |
104 In []: x, y = 1, 1.234 |
100 |
105 |
101 In []: 'x is %s, y is %s' %(x, y) |
106 In []: print 'x is %s, y is %s' %(x, y) |
102 Out[]: 'x is 1, y is 1.234' |
107 Out[]: 'x is 1, y is 1.234' |
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108 Here %s means string, you can also try %d or %f for integer and |
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109 float values. |
103 * formatting - printf style * |
110 * formatting - printf style * |
104 |
111 |
105 |
112 |
106 Now we shall look at simple input from and output to the |
113 Now we shall look at simple input from and output to the |
107 console. |
114 console. |