Python读写文件

Python读写文件

现在做CV又要开始用Python了，复习一下Python怎么读写文件23333

1. 读文件

   fin=open('<the address of file>','r')
   #read the whole file
   theWholeFile=fin.read()
   #read a line
   aLine=fin.readline()
   fin.close()
   

   如果要按字节读的话:

   fin=open('<the address of file>','rb')
   try:
       while True:
           certainBytes=fin.read(20)#read 20 Bytes one time
           if not certainBytes:#如果读完了的话
               break
   finally:
       fin.close()
   

2. 写文件

fout=open("<the address of file>",'w')
#wirte the whole text
fout.write(theWholeText)#remember if you want to write mutiple lines,please add 
 by yourself
#write mutiple lines
fout.writelines(theListofLines)
#theListofLines looks like this:
#theListofLines = ["This is 6th line
", "This is 7th line"]
fout.close()

写文件时候没有writeline方法，其实write手动在末尾加上换行符的话就是writeline，或者writekines的列表中只有一个元素也是

​ 如果要追加写的话：

fout=open("<the address of file>",'w+')

如果要写二进制文件的话：

fout=open("<the address of file>",'wb')