CSIC_716_20191107

Codec operation

Byte byte, a byte consists of 8 bit components.

Encoding process, the byte stream character to encode

Decoding process by the byte stream into character decode

What format encoding, decoding is necessary what format

 

 

 

 

 

 

Open the file in three modes

1, r mode,

　　Read-only, if the file does not exist will complain

2, w pattern

　　Write only if the file does not exist, create a file, write content

　　If the file exists, the first file of the contents emptied and the contents written into

3, a pattern

　　If the file exists, then later append content

　　If the file does not exist, create a file, write content

 

 

Open the file syntax:

Open with ( R & lt ' with the suffix of the file name ', mode = ' open mode ', encoding = ' encoding format file ') AS  F  :

r: the escape character is used to escape 'file name with the suffix' path

File name with the suffix: it can be an absolute path, or a relative path

File encoding format: file with the same coding mode can be opened

f: file objects built, to facilitate later using

for example:

with open(r'RECORD.txt', 'w', encoding='utf-8') as wf:
    wf.write('AAAAAAA')  # AAAAAAA
with open(r'RECORD.txt', 'a', encoding='utf-8')as af:
    af.write('BBBBB')  # AAAAAAABBBBB

　You can also open two simultaneous text file , a read a write-only

with open (r'RECORD.txt ',' r ', encoding =' utf-8 ') as rf, \ default when #r rt, read the text file 
        open (r'newRecord.py', 'w' , = encoding 'UTF-. 8') AS WF: 
    A = rf.read () # open file RECORD.txt 
    wf.write (a) # the file is written newRecord.py RECORD.txt

　Open pictures and other non-text files , copy when not specified encoding parameters.

with open (r'th.jpg ',' rb ') as rf, open (r'newPhoto.png', 'wb') as wf: #rb byte file for reading 
    sss = rf.read () 
    WF. write (sss)