Python Learning notes (4)

Functions of Python:

function, is a reusable program segment, we can use the call function to enable the program to achieve the same functionality, thereby greatly reducing the workload.

We can implement multiple methods in a function, by invoking various methods, to implement various functions.

The definition of a function in Python:

def function name ():

Function

When called, only the function name () or functions name is output. method () .

Cases:

Cat sayhello.py

#!/usr/bin/env python

#filename SayHello

def hello ():

print "Hello World!!!"

Def saygood ():

Print "good!!"

Version = ' 1.0 '

Hello ()

Saygood ()

Print "This version is%s"% version

This is a module where we can implement its function by invoking the method

Cat demosay.py

#!/usr/bin/env python

#filename Demosay

Import SayHello

Sayhello.hello ()

Sayhello.saygood ()

Sayhello.version

In this way, we can execute the method inside the sayhello.py to realize its function.

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Hey?!! The function is implemented, but why do we first execute the contents of sayhello.py first and then execute the function we call?

This is because the program will be initialized when loading the module, the initialization of the time, it will call the method, so that the method in our SayHello will print out through print, here is a hint, the method's return value is best not to print the output with print, but with return To return the value, only when the call to print out, it will not appear above the situation!

Then, our SayHello should be modified:

Sed-i ' s/print/return/g ' sayhello.py

Sed-i ' 4,6 s/sayhello/print sayhello/' demosay.py

The following changes are included:

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And then execute: Python demosay.py

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Okye!!!

This article is from the "Ride a Pig to Travel" blog, please be sure to keep this source http://songqinglong.blog.51cto.com/7591177/1707860

Python Learning notes (4)