import os
old_name = ‘log‘
new_name = ‘new_log‘
os.rename(old_name, new_name)

import os
os.remove("new_log")

with open(‘小护士班主任‘,encoding=‘utf-8‘) as f,open(‘小护士班主任.bak‘,‘w‘,encoding=‘utf-8‘) as f2:
    for line in f:
        if ‘星儿‘ in line:  #班主任:星儿
            line = line.replace(‘星儿‘,‘啊娇‘)
        #写文件
        f2.write(line) #小护士:金老板

import os
os.remove(‘小护士班主任‘) #删除文件
os.rename(‘小护士班主任.bak‘,‘小护士班主任‘)  #重命名文件

f = open(‘log‘, ‘r‘, encoding=‘utf-8‘)
content = f.read()
print(content)
f.close

f = open(‘log‘, ‘r‘, encoding=‘utf-8‘)
f.write(‘hello‘)
f.close()
Traceback (most recent call last):
  File "G:\very importent\Sublime Text3\Data\Packages\User\sublime\py\3.py", line 56, in <module>
    f.write(‘hello‘)
io.UnsupportedOperation: not writable

f = open(‘log‘, ‘rb‘)
content = f.read()
print(content)
print(content.decode(‘utf-8‘))
f.close()

f = open(‘log‘, ‘r+‘, encoding=‘utf-8‘)
print(f.read())
f.write(‘hello‘)
f.seek(0)
print(f.read())
f.close()

f = open(‘log‘, ‘r+b‘)
print(f.read())
f.write(‘我不好‘.encode(‘utf-8‘))
f.seek(0)
print(f.read())
f.close()

f = open(‘log‘,mode=‘w‘,encoding=‘utf-8‘)
f.write(‘骑兵步兵‘)
f.close()

f = open(‘log‘,mode=‘wb‘)
f.write(‘附近看到类似纠纷‘.encode(‘utf-8‘))
f.close()

f = open(‘log‘, mode=‘w+‘, encoding=‘utf-8‘)
f.write(‘aaa‘)
f.seek(0)
print(f.read())
f.close()

f = open(‘log‘, mode=‘w+b‘)
f.write(‘你呀的‘.encode(‘utf-8‘))
f.seek(0)
print(f.read())
print(f.read().decode(‘utf-8‘))
f.close()

f = open(‘b.txt‘,‘a‘,encoding=‘utf-8‘)
f.write(‘hello\r\nnihao ‘)
f.close()

f = open(‘log‘, ‘a‘, encoding=‘utf-8‘)
print(f.read())
f.close()
Traceback (most recent call last):
  File "G:\very importent\Sublime Text3\Data\Packages\User\sublime\py\3.py", line 60, in <module>
    print(f.read())
io.UnsupportedOperation: not readable

f = open(‘log‘, ‘a+‘, encoding=‘utf-8‘)
f.write("nihao")
f.seek(0)
print(f.read())
f.close()

f = open(‘log‘, mode=‘r‘, encoding=‘utf-8‘)
print(f.read())
f.close()

with open(‘log‘, mode=‘r‘, encoding=‘utf-8‘) as f:
    print(f.read())

f = open(‘b.txt‘,‘a+‘,encoding=‘utf-8‘)
ret = f.read()

print(ret)
f.close()

f = open(‘b.txt‘,‘a+‘,encoding=‘utf-8‘)
print(f.tell())  #tell告诉当前光标位置
f.seek(10,0)   #seek移动光标位置，第一个参数是 移动多少位      第2个参数 从什么地方开始 0: 文件开头   1当前位置   2结尾，移动到第10个字符
print(f.tell()) #
ret = f.read()
print(ret)
f.close()

f = open(‘log‘,mode=‘a+‘,encoding=‘utf-8‘)
f.write(‘佳琪‘)
count = f.tell()
f.seek(count-9)
print(f.read(2))
f.close()

with open(‘a.txt‘,‘r‘,encoding=‘utf-8‘) as f:
    f.readable()  # 是否可读
    #line = f.readline()  # 一行一行的读
    lines = f.readlines()  # 读所有行的数据，返回一个列表
    for i in lines:
        print(i)
大文件读写
方式一：循环
方式二：for i in f.readlines:

lines = ["你好eric\n", ‘你好潮装\n‘, ‘我爱python\n‘]
with open(‘多行写入.c‘, ‘w+‘, encoding=‘utf-8‘) as f:
    f.writelines(lines)
    
errors=‘ignore‘  编码不一致不报错    strict 报错。
with open(‘多行写入.c‘, ‘r+‘, encoding=‘gbk‘, errors=‘ignore‘) as f:
    print(f.read().encode(‘utf-8‘))   
方式1 ： 循环尝试   【‘gbk‘, ‘utf-8‘, ‘gbk2312‘】
方式2 ： chardet
import chardet
with open(‘a.txt‘, ‘rb‘) as f:
    data = f.read()
    print(chardet.detect(data))

with open(‘d:/sound.mp3‘, ‘rb‘) as f:
    data = f.read()
    with open(‘b.mp3‘, ‘wb‘) as f1:
        f1.write(data)

username = input(‘请输入你要注册的用户名：‘)
password = input(‘请输入你要注册的密码：‘)
with open(‘list_of_info‘,mode=‘w‘,encoding=‘utf-8‘) as f:
    f.write(‘{}\n{}‘.format(username,password))
print(‘恭喜您，注册成功‘)
lis = []
i = 0
while i < 3:
    usn = input(‘请输入你的用户名：‘)
    pwd = input(‘请输入你的密码：‘)
    with open(‘list_of_info‘,mode=‘r+‘,encoding=‘utf-8‘) as f1:
        for line in f1:
            lis.append(line)
    if usn == lis[0].strip() and pwd == lis[1].strip():
        print(‘登录成功‘)
        break
    else:print(‘账号和密码错误‘)
    i+=1