87 keyword arguments. We can call the function in a variety of ways. |
87 keyword arguments. We can call the function in a variety of ways. |
88 welcome("Hello", "James") |
88 welcome("Hello", "James") |
89 welcome("Hi", name="Guido") |
89 welcome("Hi", name="Guido") |
90 welcome(name="Guido", greet="Hello") |
90 welcome(name="Guido", greet="Hello") |
91 |
91 |
92 Keyword arguments allow us to call functions by passing arguments |
92 Keyword arguments allow us to call functions by passing arguments |
93 in any order and removes need to remember the order of arguments |
93 in any order and removes need to remember the order of arguments |
94 in the function definition. |
94 in the function definition. |
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95 |
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96 Let us look at an example function. This will both act as a code |
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97 reading exercise and tell us an important point about return |
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98 values in python's functions. Pause the video for a while and |
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99 ponder about what this piece of code does. |
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100 [show slide?] |
95 |
101 |
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102 def what( n ): |
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103 i = 1 |
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104 while i * i < n: |
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105 i += 1 |
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106 return i * i == n, i |
96 |
107 |
97 ***** return values |
108 The function takes an integer as an argument and returns the |
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109 boolean True, and the square of the number, if it is a perfect |
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110 square OR the boolean False and the square root of the next |
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111 perfect square of the number. |
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112 Note that this function is returning two values. Functions in |
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113 Python are capable of returning any number of values. |
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114 |
98 ***** arguments are local to a function |
115 ***** arguments are local to a function |
99 ***** availability library functions |
116 |
100 ***** code reading exercises? |
117 Python follows the philosophy of batteries included. It comes |
101 |
118 with a rich and versatile standard library with whole gamut of |
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119 functions. Do check out the standard library, before you sit down |
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120 to write functions of your own. |
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121 |
102 We come to the end of this tutorial on functions. In this tutorial |
122 We come to the end of this tutorial on functions. In this tutorial |
103 we have learnt about functions in a greater detail. We looked at |
123 we have learnt about functions in a greater detail. We looked at |
104 how to define functions, calling them, default and keyword |
124 how to define functions, calling them, default and keyword |
105 arguments. |
125 arguments. |
106 |
126 |