Python open read/Write File implementation script

Document directory

• 1. open
• 2. Read files
• 3. Write files

1. open

After opening a file using open, remember to call the close () method of the file object. For example, you can use the try/finally statement to ensure that the file can be closed at last. File_object = open('thefile.txt ')
Try:
All_the_text = file_object.read ()
Finally:
File_object.close ()

Note: The open statement cannot be placed in the try block, because when an exception occurs when the file is opened, the file object file_object cannot execute the close () method.

2. Read a text file Input = open ('data', 'R ')
# The second parameter defaults to r.
Input = open ('data ')

Read Binary files Input = open ('data', 'rb ')

Read all content File_object = open('thefile.txt ')
Try:
All_the_text = file_object.read ()
Finally:
File_object.close ()

Read fixed bytes File_object = open ('abinfile', 'rb ')
Try:
While True:
Chunk = file_object.read (100)
If not chunk:
Break
Do_something_with (chunk)
Finally:
File_object.close ()

Read each line List_of_all_the_lines = file_object.readlines ()

If the file is a text file, you can directly traverse the file object to get each line: For line in file_object:
Process line

3. Write a file to write a text file Output = open ('data', 'w ')

Write binary files Output = open ('data', 'wb ')

Append a file Output = open ('data', 'W + ')

Write Data File_object = open('thefile.txt ', 'w ')
File_object.write (all_the_text)
File_object.close ()

Write multiple rows File_object.writelines (list_of_text_strings)

Note that calling writelines to write multiple rows has a higher performance than using write for one-time writing.