Python的文件操作,,1、 读写文件#!/
Python的文件操作,,1、 读写文件#!/
1、 读写文件#!/usr/bin/env python# -*- coding:utf-8 -*-# @Time : 2018/1/25 20:49# @Author : zhouyuyao# @File : demonWrite.py# PyCharm 2017.3.2 (Community Edition)# Build #PC-173.4127.16, built on December 19, 2017# JRE: 1.8.0_152-release-1024-b8 amd64# JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o# Windows 10 10.0# Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) # [MSC v.1900 64 bit (AMD64)] on win32if __name__== "__main__": filename = input("Please input the name of file:") f = open(filename,"w") # 以写的形式打开一个文件 while 1: # 1 的效率是最高的 context = input("Please input context(‘EOF‘ will close file): ") if context == "EOF": f.close() break else: f.write(context) f.write("\n") fRead = open(filename) readContext = fRead.read() print("------------start-------------") print(readContext) print("-------------end--------------") fRead.close()
Please input the name of file:z.log
Please input context(‘EOF‘ will close file): hello
Please input context(‘EOF‘ will close file): the weather is cool
Please input context(‘EOF‘ will close file): you have wear more clothes
Please input context(‘EOF‘ will close file): EOF
------------start-------------
hello
the weather is cool
you have wear more clothes
-------------end--------------
2、 读取文件方法
import codecsENCODING = "utf-8" # 字符集f = open("z.log",encoding=ENCODING)print(f.name) # 文件名print(f.readline()) # 读取成列表的形式print(f.readlines()) # 读取成列表的形式with codecs.open("z.log","r",encoding=ENCODING) as f: print(f.read())
3、 Python的编码问题
编码:
支持中文的编码:utf-8,gbk,gb2312
decode 解码
encode 编码
在Python2中不定义代码的编码排头,在内容中出现中文时会报错。
Python默认将代码文件内容当做ASCII编码处理,但是ASCII编码不存在中文,因为则会抛出异常。
解决问题之道就是要让Python之道文件中使用的是什么编码形式,对于中文,可以用的常见编码有utf-8,gbk和gb2312等,只需在代码文件的最前端添加如下内容即可:
# -*- coding:utf-8 -*-
Python转码的过程:
原有编码 ——> Unicode编码 ——> 目的编码
python会自动将带中文的字符串解码成Unicode,然后再编码成gbk,因为解码是字典进行的,如果没有指明解码方式,就会使用sys,defaultencoding指明的方式来解码。
方法一:
s.decode("utf-8").encoding("gbk")
4、 Python对passwd文件进行排序
#!/usr/bin/env python# -*- coding:utf-8 -*-# @Time : 2018/1/25 23:06# @Author : zhouyuyao# @File : sortUIDPasswd.py# PyCharm 2017.3.2 (Community Edition)# Build #PC-173.4127.16, built on December 19, 2017# JRE: 1.8.0_152-release-1024-b8 amd64# JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o# Windows 10 10.0# Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) # [MSC v.1900 64 bit (AMD64)] on win32import codecsfile = "passwd"sortfile = "sortpasswd.txt"filecontext = []sortuid = []with codecs.open(sortfile,"wb") as fsort: with codecs.open(file,encoding="utf-8") as f: filecontext += f.readlines() for line in filecontext: sortuid.append(int(line.split(":")[2])) sortuid.sort() for uid in sortuid: for line in filecontext: if str(uid) == line.split(":")[2]: print(line) fsort.write(line.encode("utf-8"))
python3的新特性对文本和二进制数据作了更为清晰的区分,
文本总是Unicode,由str类型表示,
二进制则是由bytes类型表示
字符串可以encode编码成字节包,而字节包可以decode解码成字符串
Python的文件操作
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