Functions of Python

Declaring a function

Def checkname ():    a =    if a%2 ==0:        print '%s is even '% (a)        return a    else:        print '%s is odd '% (a)        return Aprint CheckName ()

DECLARE keyword def

Then a space.

And then the function name CheckName.

Then the parameter () #参数可以为空, that is, no parameter

return value #见下面介绍

-----------------------Split Line

Just a function, two places.

1. Parameters

Optional parameters: No parameter, there are 1 fixed parameters, there are many fixed parameters, fixed parameters have default values, not fixed parameters

def checkname () #无参

def checkname (b) #固定1个参数

def checkname (b = ' test ') #固定1个参数, there is a default value, that is, you can provide parameters when using, or do not provide, when not provided with the default value

def checkname (b,c) #固定2个参数

def checkname (*b) #不定长参数, which is the incoming tuple

def checkname (**b) #不定长参数, which is the incoming dictionary

2. Return value

Returns none by default when a return statement is not used

Return a returns a single member

Return (A,B.C) returns multiple members

Variables declared within a function are local variables by default and do not affect variables outside the function

If you want to influence it, you need to declare it as a global variable.

b = Onedef  values ():    global b    # declared as a globals variable    b =values ()    print b# printed here b=15= onedef  values ():     =values () print b# b=11 printed here

In general, it is not recommended to use the global variable

Add function description

def values ():     ' valuetest '    # function Description    b =print values. __doc__    # View Description

　

Functions of Python