Functions in Python, as in any other Programming language is used to run a block of code multiple times that is defined to run. by just calling the function instead of repeating the code multiple times.
- Defining a function
- Defining a function to accept parameters
- Using a return statement to return a value in a function
- Function Example : Define a function to register name and age to a Python dictionary
Functions help in reducing code redundancy and improves modularity. The below examples should help to get you started on defining and using functions.
Defining a function
Lets define a function that prints “hello!” whenever it is called
>>> def function_test():
... print("hello!")
...
>>> function_test()
hello!
>>>
Defining a function to accept parameters
A function can be defined to accept parameters that can be used in it. For instance, this function will take the name and age as parameters and use it in a print statement.
>>> def function_test(name,age):
... print "Name is %s, Age is %s" % (name, age)
...
>>> function_test('vijay', '16')
Name is vijay, Age is 16
>>> function_test('Ryan', '26')
Name is Ryan, Age is 26
Using a return statement to return a value in a function
>>> def function_test(name):
... return name
...
>>> function_test('Vijay')
'Vijay'
>>>
Function Example : Define a function to register name and age to a Python dictionary
Putting it all together, Lets define a function that registers a “name and age” to a Dictionary.
NOTE: Python Dictionary is a datatype that functions like associative arrays that records key value pairs.
>>> registry = {'john': 45, 'Ram': 21, 'singh': 32}
>>> print(registry)
{'singh': 32, 'john': 45, 'Ram': 21}
>>> def function_register(name, age):
... registry[name] = age
... print "added %s %s" % (name, age)
...
>>> function_register("vinay", "36")
added vinay 36
>>> print(registry)
{'vinay': '36', 'singh': 32, 'john': 45, 'Ram': 21}
>>>
>>> function_register("victor", "29")
added victor 29
>>>
>>> print(registry)
{'vinay': '36', 'singh': 32, 'john': 45, 'Ram': 21, 'victor': '29'}
>>>
