三、循环

1. 两种循环语句

• while循环
  e.g.

i = 1
sum = 0

while i <= 10:
      sum += i
      i += 1
print(sum)

总结为：

while 条件:
      循环体

• for循环
  e.g.

for each in "python":
      print(each)

sum = 0
for i in range(101):
     sum += i
print(sum) 

总结为：

for 变量 in 可迭代对象:
      循环体

2. 循环的终止

• break语句
  作用：终止当前整个循环
  e.g.

for each in "python":
      print(each)
      if each  == 'o':
         break

• continue语句
  作用：跳出本轮循环并开始下一轮循环
  e.g.

for each in "python":
      if each  == 'o':
         continue
      print(each)

PS: while循环和for循环可以随意组合嵌套