Python Open Read-write file Implementation script

1.open

Always remember to call the close () method of the file object after opening the file with open. For example, you can use the Try/finally statement to ensure that the file is 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 the file object File_object cannot execute the close () method when an exception is opened to the file.

2. Read the file

Read text file

input = open (' Data ', ' r ') #第二个参数默认为rinput = 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 byte

File_object = open (' Abinfile ', ' RB ') Try: While  True:    chunk = file_object.read (+)    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 also traverse the file object directly to get each line:

For line in File_object:
Process Line

3. Writing files

Write a text file
Output = open (' Data ', ' W ')

Write a binary file
Output = open (' Data ', ' WB ')

Append Write file
Output = open (' Data ', ' w+ ')

Write Data

File_object = open (' Thefile.txt ', ' W ') File_object.write (All_the_text) file_object.close ()

Write Multiple lines
File_object.writelines (list_of_text_strings)

Note that calling Writelines writes multiple rows at a higher performance than using write one-time writes.

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