例子

# #循环所有的奇数双数
# a = 1
# while a < 101:
#     if a % 2 == 0:
#         print(a)
#     a += 1
#
# #循环1-100所有的偶数单数
# a = 1
# while a < 100:
#     if a % 2 == 1:
#         print(a)
#     a += 1
#
# #循环1-10
# a = 1
# while a < 11:
#     print(a)
#     a += 1
# #循环1-10没有7
# a = 0
# while a < 10:
#     a += 1
#     if a == 7:
#         continue
#     print(a)
#
# a = 1
# while True:
#     if a == 7:
#         a += 1
#         continue
#     elif a == 11:
#         break
#     print(a)
#     a += 1

# name = input("请输入你的名字")
# age = int(input("请输入你的年龄"))
# job = input("请输入你的工作")
# hobbie = input("请输入你的爱好")
# a = '''
# -----------欢迎登录   %s ------------
# name = %s
# age = %d
# job = %s
# hobbie = %s
# --------------end--------------------
# '''%(name,name,age,job,hobbie)
# print(a)

#用户登录且能登录三次
# a = 0
# while a < 3:
#     a += 1
#     s = input("请输入你的账号")
#     d = input("请输入你的密码")
#     if s == "123" and d == "456":
#         print("登录成功")
#         break
#     else:
#         print("登录失败")
#         continue
#用户登录且只要愿意就能一直登录
# username = "congcong"
# password = "123"
# i = 0
# while i < 3:
#     name = input("请输入你的用户名")
#     pwd = input("请输入你的密码")
#     if username == name and password == pwd:
#         print('您登录成功')
#         break
#     else:
#         print("登录失败，您还有%d次机会"%(2-i))
#         if (2-i) == 0:
#             result = input("是否还想再试试？Yes   ")
#             if result == "Yes":
#                 i = 0
#                 continue
#     i += 1
# else:print("呵呵")