Getting started with Python-Process Control __python

This article describes process control (conditional statements and circular statements) in Python

1, conditional statement

(1) only if

A=true
If a:
    print ("A is established")
    print ("I know A is established")

(2) If---else

A=true
If a: print ("A is established"
    )
    print ("I know A is established")
else:
    print ("A does not set up")

(3) If---elif---else

A=false
b=true
If a:
    print ("AAA")
elif B:
    print ("bbbb")
else:
    print ("CCC")

2. Circular statements

(1) for

Similar to the use of foreach

letter=[111, "Zhangshan", 7878,99] for Le in letter
:
    print (LE)

Traversing using the subscript index

letter=[111, "Zhangshan", 7878,99,88] for
index in range (len):
    print (Letter[index))

With else for, when the condition is not true, execute else

letter=[111, "Zhangshan", 7878,99] for Le in letter
:
    print (le)
else:
    print ("Loop over")

(2) While note: There is no do---in python while

General while

A=1 while
a<=4:
    print (a)
    a+=1

A while with else, executing else when the condition is not true

I=0 while
i<5:
    print ("i")
    i+=1
Else:
    print ("Conditional not set")