Python-if Statement Control

If Else

A logical value contains two values

Ture: Represents a non-empty amount (string,tuple,list,set,dictionary), all non-zero.

Flase: Represents the amount of 0,none, empty.

elif statements

If expression1:

Statement1 (s)

Elif expression2:

Statement2 (s)

Elif Expression3:

Statement3 (s)

Else

STATEMENT4 (s)

Converting a string to uppercase and lowercase

A= ' abc '

A.lower () changes the string to lowercase.

#!/usr/bin/python

Yn = raw_input ("Please input [yes/no]:")

Yn = Yn.lower ()

If yn = = ' y ' or yn = = ' yes ':

Print "Programe is running ..."

Elif yn = = ' n ' or yn = = ' no ':

Print "Programe is Exit"

Else

print "Please input [yes/no]:"

Python Process Control loop

A loop is a structure that causes the program to repeat a certain number of times.

The same is true for conditional loops, where the loop ends when the condition is false

For loop:

In the sequence, use the For loop to traverse

The range function is also a sequence

Range (10)

List rewrite, which powers the value of I:

Print [i**2 for I in range (1,11) if I% 2 = = 0]

Calculation 1: 100 's and:

#!/usr/bin/python

sum = 0

For I in range (1,100):

sum = sum + I//or write as Sum+=i

Print sum

Range return is a list of the resulting

Xrange and range are similar, faster than range

Xrange does not produce a list, but an object that can be assigned to a variable and then evaluated by traversing the object.

Xrange is relatively less resource-intensive because it is placed in memory.

loop Control-For dictionary

DIC = {' A ': 1, ' B ': 2}

For k,v in Dic.iteritems ():p rint k,v

A 1

B 2

Write a multiplication formula: use nested

#!/usr/bin/python

For I in Xrange (1,10): Control number of rows

For j in Xrange (1,i+1): Control Number of columns

Print "%sx%s=%s"% (j,i,j*i),

Print

650) this.width=650; "Src=" Http://s3.51cto.com/wyfs02/M00/83/9E/wKioL1d4r3rQXfXmAAAgfpF0r4I640.png-wh_500x0-wm_3 -wmp_4-s_3288033790.png "title=" Ss.png "alt=" Wkiol1d4r3rqxfxmaaagfpf0r4i640.png-wh_50 "/>

This article is from the "less stubborn" blog, please be sure to keep this source http://xushaojie.blog.51cto.com/6205370/1795287

Python-if Statement Control