Python基础三

# input = input('age>>:')
# input = int(input)
# if input > 18:
#     print('大了')
# elif input < 18:
#     print('小了')
# else:
#     print('ok')
# count = 0
# while count <= 10:
#     print(count)
#     count += 1
# count = 0
# while count <= 10:
#     print(count)
#     count += 1
# count = 1
# while count <= 10:
#     if count == 7:
#         break
#     print(count)
#     count += 1
# count = 1
# while count <= 10:
#     if count == 4:
#         count += 1
#         continue # 跳过本次循环，后面的循环都不执行
#     print(count)
#     count += 1
# name = input('name>>:')
# paseword = input('paseword>>:')
# if name == 'rambo' and paseword == '123':
#     print('登陆成功')
# else:
#     print('用户名或者密码错误')
# while True: # 全选+tab键 全部向前缩进 &&&&&&&&&&
#             #    tab+shift键 全部向后缩进 **********
#     name = input('name>>:')
#     paseword = input('paseword>>:')
#     if name == 'rambo' and paseword == '123':
#         print('登陆成功')
#     else:
#         print('用户名或者密码错误')
# count = 1
# while True:
#     if count > 3:
#         break # break之后的都不运行了
#     name = input('name>>:')
#     paseword = input('paseword>>:')
#     if name == 'rambo' and paseword == '123':
#         print('登陆成功')
#     else:
#         print('用户名或者密码错误')
#     count += 1
# count = 1
# while True:
#     if count > 3:
#         break # break之后的都不运行了
#     name = input('name>>:')
#     paseword = input('paseword>>:')
#     if name == 'rambo' and paseword == '123':
#         print('登陆成功')
#         while True:
#             cmd=input('name>>:')
#             if cmd == 'sean':
#                 break
#             print('run %s' %cmd) # 执行命令！执行命令！执行命令！执行命令！执行命令！执行命令！执行命令！
#         break # 结束本层循环
#     else:
#         print('用户名或者密码错误')
#     count += 1
# count = 1
# tag = True
# while tag:
#     if count > 3:
#         break # break之后的都不运行了
#     name = input('name>>:')
#     paseword = input('paseword>>:')
#     if name == 'rambo' and paseword == '123':
#         print('登陆成功')
#         while tag:
#             cmd=input('name>>:')
#             if cmd == 'sean':
#                 tag = False
#                 continue
#             print('run %s' %cmd) # 执行命令！执行命令！执行命令！执行命令！执行命令！执行命令！执行命令！
#     else:
#         print('用户名或者密码错误')
#     count += 1
# count = 0
# while count < 7:
#     print(count)
#     count += 1
# else:
#     print('当while在运行过程中没有被break打断时，执行')
# count = 0
# while count < 7:
#     if count == 4:
#         break
#     print(count)
#     count += 1
# else:               #    了解！！！！！！
#     print('当while在运行过程中没有被break打断时，运行')
# 字符串里的单个字符是可以取出来的，
# msg='hello world'
# print(msg[0]) # 得到h 按照索引取值，正向取
# print(msg[-1]) # 得到d 按照索引取值，反向取
# 字符串是不可变类型，python中没有单个字符
# print(msg[0:3])# =< 0 <3 切片，顾头不顾尾 hel
# print(msg[0:7])# =< 0 <7 切片，顾头不顾尾 空格也算字符 hello w
# print(msg[0:7:2])# =< 0 <3 切片，顾头不顾尾 步长为2 hlow
# print(msg[5:0:-1])# =< 0 <3 切片，顾头不顾尾 倒着取 步长为1  olle
# print(msg[-1:0:-1])# =< 0 <3 切片，顾头不顾尾 倒着取 步长为1 dlrow olle
# print(msg[-1::-1])# =< 0 <3 切片，顾头不顾尾 倒着取 步长为1 dlrow olleh
# print(msg.__len__()) # 11 长度
# print(len(msg)) # 11 len调用 “msg.__len__() ”python内部调用的功能
# 成员运算 in not in
# print('llo' in msg) # True
# 移除空白 strip 用法.strip()
# password='        deicbricbr        '  用法.strip()
# print(password.strip()) # deicbricbr  用法.strip()
# password=input('>>:').strip()  用法.strip()
# print(password)  用法.strip()
# password='asdf  1234  ' 字符中间的空格不会去掉
# print(password) # asdf  1234  字符中间的空格不会去掉
# 切分 split
# user_info='root:123:/1:asdf'
# cmd=user_info.split(':') 命令符为：
# print(cmd) # ['root', '123', '/1', 'asdf']
# print(cmd[0]) # root
# file='salary /kook1/book/asdf'
# cmd=file.split()
# print(cmd) # ['salary', '/kook1/book/asdf']
# print(file.split()[0]) # salary
# file='c:\a\b\c.txt'
# print(file.split('\')[0]) # c:
# print(file.split('\',1)) # ['c:', 'a\b\c.txt']
# print(file.rsplit('\',1)) # ['c:\a\b', 'c.txt']
# msg='hello world'
# print(len(msg))
# n = 0
# size=len(msg)
# while n < size:
#     print(msg[n])
#     n += 1
# for i in msg:
#     print(i)