python流程控制

4.流程控制和循环

age = raw_input('age:')

if  age>40:

    print  'old!'

elif  age>30:

    print  'young!'

else:

    print 'younger!'

if执行到情况匹配时就直接结束，并不是退出

else也可以省略

变量的声明等号  = 

赋值的定义是双等号   == 

 

for循环

for  *  in  * ：

 

5.while循环

while循环默认是死循环

for循环有起始结束，循环次数

 

print_num = input('which loop do you want it to be printed out?')

count = 0

while count < 100000:

       if count == print_num:

            print 'There you got  the number:',count

            choice = raw_input('Do you want to continue the loop?(y/n)')

            if choice == 'n':

                 break

            else:

                  while print_num <= count:

                         print_num = inout('Which loop do you want it to be printed out?')

                         print u"pass"

       else:

              print 'Loop:',count

       count  +=1      

 

else:

      print 'loop:',count