#if-else
    if a > b:
        print(‘aaa‘)
    else:
        print(‘bbb‘)

#if-elif-else
    if a > b:
        print(‘a>b‘)
    elif a == b:
        print(‘a==b‘)
    else:
        print(‘a<b‘)

while 判断条件:
    执行语句

for temp in sequence:
    执行语句

#-*- coding:utf-8 -*-
for letter in ‘python‘:
　　print(‘current letter is %s‘%letter)

#-*- coding:utf-8 -*-
fruits = [‘banner‘,‘apple‘,‘orange‘]
for fruit in fruits:
     print(‘current fruit is %s‘%fruit)