循环（点点滴滴）

循环

# while循环
# 1.在一定条件下，重复做某件事件（代码）
# 2.while循环
#     1.当条件表达式 == True 才执行循环内容
#     2.循环的递增变量
sumData = 0
cnt = 1
while cnt <101:
    sumData += cnt
    cnt += 1
print(sumData)

#     3.死循环，不一定是bug，有优点，有用途
#     4.一般功能上的死循环都是结合一定条件下的  break
 while True:
     psw = input("请输入密码：")
     print("你在循环中，按q退出！")
     if psw == "q":
         break
# for 循环
# 先体验下while
 alist = ["a", "b", "c", "d", "e", "f"]
 cnt = 0
 while cnt <6:
     print(alist[cnt])
     cnt += 1

”’
结果：
a
b
c
d
e
f
”’

# 再看for  遍历
 alist = ["a", "b", "c", "d", "e", "f"]
 for i in alist:
     print(i)
'''

结果：
a
b
c
d
e
f
”’

# 打印1到10   range左含右不含
 for i in range (1,11):
     print(i)
'''

1
2
3
4
5
6
7
8
9
10
”’

# 打印1到100的和
 sumData = 0
 for i in range (1,101):
     sumData += i
 print(sumData)

# break 跳出本层循环
 alist = ["a", "b", "c", "d", "e", "f"]
 for i in range(0,2):  #两次 0 1
     for name in alist:
         print(name)
         if name == "b":
             break
 print("over")

# 结果：
'''
a
b
a
b
over
'''

# continue   跳出本次循环
alist = ["a", "b", "c", "d", "e", "f"]
for i in range(0, 2):  # 两次 0 1
    for name in alist:
        if name == "b":
            continue
        print(name)
print("over")

# 结果
'''
a
c
d
e
f
a
c
d
e
f
over
'''

# 函数内部注释：
def func():
    "这个是函数的注释"
    print("函数")


print(func.__doc__)
# 结果：这个是函数的注释