1.读取一个文件，显示除了井号(#)开头的行意外的所有行
# -*- coding: utf-8 -*-
"""
Created on Tue May 28 09:37:08 2019
@author: Omega_Sendoh
"""
#打开文件
f = open("install-sh","r")
#读取文件的所有行，以列表形式存储，每行为列表中的一个字符串元素
res = f.readlines()
#循环整个列表，去除以空格开头的行的空格，然后去除以#号开头的行的#号
for i in res:
if i[0] == "#":
continue
else:
print(i)
2.无重复字符的最长子串
# -*- coding: utf-8 -*-
"""
Created on Tue May 28 10:57:55 2019
@author: Omega_Sendoh
"""
"""
定义一个空的字符串，从起始位置开始搜索输入的字符串，如果字符没有出现在wind中，则把字符加入wind
如果字符出现在wind中，则找到字符串中出现该相同字符的位置，删除该重复字符之前的所有字符
并重新加入该字符
"""
def LongestString(s):
wind = ''
l=0
for i in s:
if i not in wind:
wind +=i
l=max(l,len(wind))
else:
wind = wind[wind.index(i)+1:] + i
return l
s=input('enter string:')
print(LongestString(s))
3.制作一个密码簿，其可以存储一个网址，和一个密码，请编写程序完成这个密码簿的增删改查功能，并且实现文件存储功能。
import json
def add_info():
#打开存储文件，判断文件中是否有内容
with open('usr.json','a+') as f:
info = f.read()
#如果没有内容，创建一个字典，以字典的方式存储网址与密码
if not info:
with open('usr.json','a+') as f:
full_info = {}
net_add = input('enter your URL:')
passwd = input('enter your password:')
full_info[net_add] = passwd
print('add success')
json.dump(full_info,f)
#若文件中有内容，则把文件中的内容转换为python的字典类型
else:
with open('usr.json','r') as f :
full_info = json.load(f)
#print((full_info))
net_add = input('enter your URL:')
passwd = input('enter your password:')
full_info.setdefault(net_add,passwd)
print('add success')
#给字典中添加对象，再次写入文件中(即添加新的信息后重新更新文件的内容)
with open('usr.json','w') as f :
json.dump(full_info,f)
def del_info():
with open('usr.json','r') as f:
full_info = json.load(f)
#输入想要删除的网址
net_add = input('enter your delete URL:')
#如果该网址存在，则删除网址与密码，把更改后的数据存到文件中
if net_add in full_info:
del full_info[net_add]
print('delete success')
with open('usr.json','w') as f:
json.dump(full_info,f)
#若该网址不存在，提示网址不存在
else:
print('This URL not exist')
def change_info():
with open('usr.json','r') as f:
full_info = json.load(f)
#输入要更改的网址与密码
net_add = input('enter your change URL:')
passwd = input('enter your new password:')
if net_add in full_info:
full_info[net_add] = passwd
print('change password succcess')
with open('usr.json','w') as f:
json.dump(full_info,f)
else:
print('This URL not exist')
def check_info():
with open('usr.json','r') as f:
full_info = json.load(f)
net_add = input('enter your check URL:')
if net_add in full_info:
print('This URL password is:',full_info[net_add])
else:
print('This URL not exist')
print('you can choose: add/del/change/check/quit')
while 1:
obj = input('enter your choose:')
if obj == 'add':
add_info()
elif obj == 'del':
del_info()
elif obj == 'change':
change_info()
elif obj == 'check':
check_info()
else:
break
运行结果：
