Python Custom functions

Introductionin Python, you define a function to use a def statement, write out the function name, parentheses, the arguments in parentheses, and a colon : , and then, in the indent block, write the function body, the return value of the function is returned with a return statement, and return satisfies the condition and no longer executes the following statement. Print output is also available. 1. Defining FunctionsCustomize a judgment function for an age period when the input age is greater than or equal to 18 to return ' adult ' if the value entered is non-cosmetic and returns an error

#!/usr/bin/Env python3#-*-coding:utf-8-*-#file:d ef_agedef my_age (x):ifNot Isinstance (x, (int)): Raise TypeError ('Bad operand type') Elif x>= -:        return('Adult') Elif x<7:        return(' Child')    Else:        return(' Young')

2. Calling a custom function

There are three ways to invoke custom functions

1. If the custom function has been saved as a file,

 from def_age Import my_age>>> my_age ()'adult'

Open the compiler in the file directory, since the custom function is not an intrinsic function, you need to import the function first, note that Def_age does not need to have a suffix. py

2. Call the given value inside the code

#!/usr/bin/Env python3#-*-coding:utf-8-*-#file:d ef_agedef my_age (x):ifNot Isinstance (x, (int)): Raise TypeError ('Bad operand type') Elif x>= -:        return('Adult') Elif x<7:        return(' Child')    Else:        return(' Young') Print (My_age ( A))

You do not need to import functions to execute files directly, but this method is not flexible enough.

3. Define variables before calling functions inside the code

#!/usr/bin/Env python3#-*-coding:utf-8-*-#file:d ef_agedef my_age (x):ifNot Isinstance (x, (int)): Raise TypeError ('Bad operand type') Elif x>= -:        return('Adult') Elif x<7:        return(' Child')    Else:        return(' Young') Age= APrint (My_age (age))

The same approach is not flexible enough.

3. Create an empty functionAn empty function, which is a function that does not contain execution code, uses pass as a block of code, and the pass code does nothing; sometimes a piece of code is not ready to be written in order to not affect the entire code to run, you can first save the pass to let the code run first.

Def my_dinf ():    Pass

Pass can also be placed in other code, such as:

#!/usr/bin/Env python3#-*-coding:utf-8-*-#file:d ef_agedef my_age (x):ifNot Isinstance (x, (int)): Raise TypeError ('Bad operand type') Elif x>= -: Pass Elif x<7:        return(' Child')    Else:        return(' Young') Age= APrint (My_age (age))

Or just the age of the judgment function, now in the Elif x>=18: code block below the use of pass, when the condition is satisfied after doing nothing, the entire code is executed normally.

Summary

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Python Custom functions