Step Into Python World (vi) Process Control 2. Branch Control (Swith)

In most programming languages, there are branch control statement switch.

The switch statement is used to write a multi-branch structure program, similar to the If...elif...else statement

The branching structure expressed by the Swith statement is clearer than the If...elif...else statement, and the code is more readable.

But Python does not provide a switch statement

The switch implementation in Python

Python can implement the switch statement function through a dictionary

The implementation method is divided into two cloth

First, define a dictionary

Second, get the corresponding expression using the get () of the dictionary

Function call

Calling a function from a dictionary, returning the corresponding value

{1:case1,2:case}.get (X,lambda*args,**key:) ()

From __future__ Import Division # # #引入除法模块def Jia (x, y): Return x+ydef Jian (x, y): Return x-ydef cheng (x, y): return X*ydef Chu (x, y): return x/y operator = {"+": Jia, "-": Jian, "*", Cheng, "/": Chu}print Chu ##### Printing method object Print operator["/" ] (3,2) ###### print out 1.5print operator["("] (3.2) ###### error, no key value (Def f (x,o,y): Print Operator.get (o) (x, y) print Opera Tor.get (0) (X,y,*args,**kwargs) F (3, "+", 2) # # # # # # # # Print out 5

Step Into Python World (vi) Process Control 2. Branch Control (Swith)