day3 文件操作 seek tell 修改

#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:DCC
#
##默认读取模式
file = open("test_file","r",encoding="utf-8") #文件句柄
print(file.read())
data = file.read() #所有内容
data1 = file.read() #第二次读，是读不出数据的
file.seek(0)  #将光标归零
data2 = file.read() #光标归零后就可以再出读出数据
file.close()

#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:DCC
file = open("test_file","r",encoding="utf-8") #文件句柄
print(file.read()) #读出全部
file.seek(0)
print(file.readline()) #读出一行
file.seek(0)
print(file.readlines()) #把文章内容以换行符分割，并生成list格式


C:\Users\congcong.du\AppData\Local\Programs\Python\Python35\python.exe C:/Users/congcong.du/PycharmProjects/test/day3/file.py
1如果你真的爱我 让我走开
2心疼你当初反覆那样的说
3如果你真的爱我 让我走开
4我决心不从旧梦中 挣脱
5如果你真的爱我 让我走开
6心疼你为我藏住分离的苦
7如果我知道你是这样的难过
8会一个人走向寂寞
1如果你真的爱我 让我走开

[‘1如果你真的爱我 让我走开\n‘, ‘2心疼你当初反覆那样的说\n‘, ‘3如果你真的爱我 让我走开\n‘, ‘4我决心不从旧梦中 挣脱\n‘, ‘5如果你真的爱我 让我走开\n‘, ‘6心疼你为我藏住分离的苦\n‘, ‘7如果我知道你是这样的难过\n‘, ‘8会一个人走向寂寞‘]

file = open("test_file","r",encoding="utf-8") #文件句柄
for i in range(5):
    print(file.readline()) #读出前五行
file.close()

for line in file.readlines(): #转化为列表格式了
    print(line.strip())

#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:DCC
file = open("test_file","r",encoding="utf-8") #文件句柄
#将文件全部读入内存
for index,line in enumerate(file.readlines()): #读列表和下标
    if index == 9:
        print("-----------------")
        continue
    print(line.strip())
‘‘‘
#这个效率最高，for line in file,逐行读到内存
‘‘‘
count = 0
for line in file:
    if count == 9:
        print("--------------------")
        count += 1
        continue
    print(line)
    count += 1
‘‘‘

#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:DCC
##默认读取模式
file = open("test_file","r",encoding="utf-8") #文件句柄
print(file.tell()) #打印光标当前的位置
print(file.readline())
print(file.readline())
print(file.readline())
print(file.tell())
file.seek(0)  #移动归零
print(file.tell())
file.flush #刷新，从内存写到磁盘

file.close()

C:\Users\congcong.du\AppData\Local\Programs\Python\Python35\python.exe C:/Users/congcong.du/PycharmProjects/test/day3/file.py
0
1如果你真的爱我 让我走开

2心疼你当初反覆那样的说

3如果你真的爱我 让我走开

110
0

#!/usr/bin/env python
#-*- coding:utf-8 -*-
# Author:DCC
#修改思路：打开一个文件，从旧文件，读一行写一行，改一行，写一行
f = open("test_file","r",encoding="utf-8")
f_new = open("test_file.bak","w",encoding="utf-8")
for line in f:
    if "心疼" in line:
        line = line.replace("心疼","xinteng")
        print(line)
    f_new.write(line)
f.close()
f_new.close()

#with
#python 一行不要超过80个字符，用换行\
with open("yesterday","r",encoding="utf-8") as f,open("yesterday2","r",encoding="utf-8") as f2:
    for line in f:
        print(line)
    for line2 in f2:
        print(line2)