Python study NOTE 2: Process Control and python study note Process

Python study NOTE 2: Process Control and python study note Process
1. if else:

#!/usr/bin/pythonx = int(raw_input('please input:'))if x >= 90:    if x >= 95:        print 'a+'    else:        print 'a'elif x >= 80:    if x >= 85:        print 'b+'    else:        print 'b'elif x >= 70:    if x >= 75:        print 'c+'    else:        print 'c'else:    if x >= 60:        print 'd+'    else:        print 'bad'

Ii. logical operators and or not

#!/usr/bin/pythonx = int(raw_input('please input x:'))y = int(raw_input('please input y:'))if x >= 90 and y >= 90:    print 'a'elif x >= 80 or y >= 80:    print 'b'elif not x < 60 and (not y < 60):    print 'c'else:    print 'bad'

3.

Sequence:

#!/usr/bin/pythons = "hello python"for x in s:    print xfor index in range(len(s)):    print s[index]

Dictionary:

#!/usr/bin/pythondic = {'a':1,'b':2,'c':3}for x in dic:    print x,dic[x]for k,v in dic.items():    print k,v

Control

Else: after normal execution of for, the content in else will be executed; otherwise, no (press Ctrl + c for the following code execution process)

#!/usr/bin/pythonimport timefor x in range(10):    print x    time.sleep(1)else:    print 'end'

Break: jump out of the current loop

#!/usr/bin/pythonfor x in range(10):    print x    if x == 6:        breakelse:    print 'end'

Content in else will not be executed here

Pass: placeholder

Exit: exit

#!/usr/bin/pythonfor x in range(10):    print x    if x == 2:        print 'hello',x        continue    if x == 4:        pass    if x == 5:        exit()    if x == 6:        break    print '*'*10else:    print 'end'

4. while

If the condition fails, it will be executed after it ends normally. If break is executed, it will not be executed in else.

#!/usr/bin/pythonx = 'hello'while x != "q":    print x    x = raw_input('please input something,q for quit:')    if not x:        breakelse:    print 'ending'