#f= open(r"aaa/a.txt",mode='rt') # f的值是一种变量，占用的是应用程序的内存空间,此时牵扯的是两个方面的资源

#print(f)

##2.操作文件：读/写文件,应用程序对文件的读写请求都是向操作系统调用，然后由操作系统控制把硬盘把输入读入内存，或者写入硬盘

#res=f.read()

#print(res)

#关闭文件 z

#f.close()"""回收操作系统资源，f 还存在"""

#f变量还存在，但是不能再读了

#del f """回收应用程序程序资源"""

#文件对象又称为文件句柄

# with open("a.txt",mode='rt') as f1:

# res=f1.read()

# print(res)

# with open("a.txt",mode='rt') as f1,open("b.txt",mode='rt') as f2:

# res1=f1.read()

# res2=f2.read()

# print(res1)

# print(res2)

"""指定字符编码"""

"""t 文本(默认的模式)

1。 读写都是以str (unicode)为单位的

2。文本文件

3。必须指定encoding='utf-8'"""

# 没有指定encoding 参数操作系统会使用自己的默认的编码，

# Linux 和mac 默认使用utf-8

# Windows默认gbk

# with open ('c.txt',mode='rt',encoding='utf-8') as f:

# res=f.read() #t模式会将f.read()读出来的结果解码成unicode

# print(res,type(res))

#

#内存：utf-8格式的二进制----解码--->unicode

#硬盘(c.txt 内容 utf-8格式的二进制)

#以t 模式为基础进行内存操作

##1.rt

在本python文件的目录下创建一个name.txt的文本文件，

izhan:1005

inp_username = input("please input your name:").strip()

inp_password = input("please input your password:").strip()

with open("name.txt",mode='rt',encoding='utf-8') as f:

res=f.read()

print(res)

username,password=res.split(":")

print(username)

print(password)

print(inp_username)

print(inp_password)

if inp_username == username and inp_password == password:

print("congratulations! you can login")

else:

print("sorry! the password is wrong or has no this user")

please input your name:izhan

please input your password:1005

izhan

1005

izhan

1005

congratulations! you can login

随便输入看看：

please input your name:dandan

please input your password:0711

izhan

1005

dandan

0711

sorry! the password is wrong or has no this user

Process finished with exit code 0

再创建一个name.txt 文件

izhan:1005

lili:1111

dandan:0711

另外：python spit 的学习：

https://www.cnblogs.com/clairedandan/p/10926173.html

inp_username = input("please input your name:").strip()

inp_password = input("please input your password:").strip()

with open("name.txt",mode='rt',encoding='utf-8') as f:

for line in f:

print(line,end='') # 没有end='',结果就会一行一行中间有一行空的。

username,password=line.strip().split(":")

# print(username)

# print(password)

if inp_username == username and inp_password == password:

print("login successfully")

break

else:

print("账号错误")

please input your name:lili

please input your password:0711

izhan:1005

lili:1111

dandan:0711账号错误

Process finished with exit code 0

please input your name:izhan

please input your password:1005

izhan:1005

login successfully

Process finished with exit code 0

"""w:只写模式，当文件不存在时会创造空文件，当文件存在时会清空文件，"""

# with open("d.txt",mode="wt",encoding="utf-8") as f:

# # f.read()"""报错，不可读"""

# f.write("hahaha\n")

# f.write("hello\n")

# f.write("wwwwww\n")

##如果重新打开文件，则会清空之前的内容，如果连续write，则会连续写的

"""3.a 只追加写，"""

# with open("a.txt",mode="at",encoding="utf-8") as f:

# # f.read() 不能读

# f.write("hahahahah\n")

# f.write("enenenenen\n")

# f.write("oooooo\n")

"""a 重新打开文件，不会清空文件内容，会将文件指针直接移动到末尾

a 文件一直用作记录日志，注册功能"""

"""a 模式注册功能"""

# name=input("please input your name:")

# pwd=input("please input your password:")

# with open("db.txt",mode="at",encoding="utf-8") as f:

# f.write("{}:{}\n".format(name,pwd))

w 可以用做文本文件的copy

with open("e.txt",mode="rt",encoding="utf=8")as f1,\

open("f.txt",mode="wt",encoding="utf-8")as f2:

res=f1.read()

f2.write(res)

src_file=input("源文件文件：")

dst_file=input("目标文件：")

with open(r"{}".format(src_file),mode="rt",encoding="utf=8")as f1,\

open(r"{}".format(dst_file),mode="wt",encoding="utf-8")as f2:

res=f1.read()

f2.write(res)

/usr/local/bin/python3.8 /Users/futantan/PycharmProjects/S14/文件知识/文件处理.py

源文件文件：/Users/futantan/PycharmProjects/S14/文件知识/a.txt

目标文件：/Users/futantan/PycharmProjects/S14/a_copy.txt

Process finished with exit code 0

此时就可以发现有一个copy的文件了

标签：txt,python,res,--,详解,mode,print,input,password

来源： https://www.cnblogs.com/clairedandan/p/14105609.html