3.python 控制文件读写内容以及操作模式

 1.实现

inp_username=input( "name:" ).strip()
inp_password=input( "password:" ).strip()
with  open ( 'x.txt' ,mode= 'rt' ,encoding= 'utf-8' ) as f:
    for line  in f:
        username,password=line.strip(). split ( ':' )
        if inp_username == username and inp_password == password:
            print( "successful" )
            break
    else :
        print( 'error' )

　　

 2.

with  open ( 'x.txt' ,mode= 'wt' ,encoding= 'utf-8' ) as f:
    f.write( '哈哈哈\n' )

　　

 

 3.

with open('E.TXT',mode='at',encoding='utf-8') as f:
    f.write('c1\n')
    f.write('c2\n')

　　

4.

src_file=input('源文件路径》》：').strip()
dst_file=input('目标文件路径》》：').strip()
with open(r'{}'.format(src_file),mode='rt',encoding='utf-8') as f,\
    open(r'{}'.format(dst_file),mode='wt',encoding='utf-8') as g:
    res=f.read()
    g.write(res)

　　

#了解+
#r+
''' 
with open('b.txt',mode='rt+',encoding='utf-8') as f:
    print(f.read())
    f.write('liuyan')
'''
#w+
'''
with open('b.txt',mode='wt+',encoding='utf-8') as f:
    print(f.read())
    f.write('liuyan\n')
    f.write('liuyan\n')
'''

#a+
with open('b.txt',mode='at+',encoding='utf-8')as f:
    print(f.read())
    f.write('xxxxx\n')
    f.write('zzzzzz\n')