Python基础（ ）

一. 文件修改

f = open("yesterday.txt",'r')
f1 = open("yesterday2.txt",'w')
for line in f:
    if "会不会比较睡得着，" in line:
        line = line.replace("会不会比较睡得着，","shagouzi")   #replace行替换，注意顺序
    f1.write(line)

f.close()
f1.close()

with语句

为了避免打开文件后忘记关闭，可以通过with管理上下文：

with open("yesterday.txt",'r') as f:      #格式：  # 有冒号，下行缩进
    print(f.read())

with open("yesterday.txt",'r') as f1,open("yesterday2.txt",'r') as f2:      #可以同时打开多个文件
    print(f1.read())
    print(20*'-')
    print(f2.read())

二. 字符编码与转码

import sys
print(sys.getdefaultencoding())     #打印系统默认编码

s = "哈喽"
s_gbk = s.encode("gbk")

print(s_gbk)
print(s.encode())

gbk_to_utf8 = s_gbk.decode("gbk").encode("utf-8")
print("utf8",gbk_to_utf8)

大家参考大牛的博客吧：http://www.cnblogs.com/luotianshuai/articles/5735051.html