Python v. Python file object

I. file systems and documentation

1. File systems and files

A file system is the method and data structure used by the OS to clear files on a disk or partition-the method of organizing files on disk

computer files (or files, computer archives, files) are a stream of data stored in a long-term storage device or temporary storage device, and belong to the computer file system Management

Generally speaking:

A file is a name-controlled storage area of the computer that is managed by the OS

On a Linux system, a file is considered a sequence of bytes

2. Architecture of Linux File system components

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3. Python Open File

Python built-in function open () for opening files and creating file objects

Syntax format:

open (Name[,mode[,bufsize]])

The Open method can receive three parameters: file name, pattern, and buffer parameters

The open function returns a file object

Mode: Specifies the open mode of the file

BufSize: Defining output caching

0 indicates no output cache

1 indicates the use of buffering

Negative numbers mean using system default settings

A positive number indicates a buffer with an approximate specified size

4. Open mode of File

Simple mode:

R: Read-only

Open ('/var/log/message.log ', ' R ')

W: Write

A: Additional

Use "+" after pattern to support input and output operations at the same time

such as r+, w+ and A +

Append "B" to the pattern to open in binary mode

such as RB, wb+

5. File method

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The file object maintains the state of the file it opens, and its tell () method returns the current position in the open file

The read () method is used to read a file into a single string, or it can specify the number of bytes to read

ReadLine () can read the next line to a string, including the Terminator of the end of the line

ReadLines () reads all lines of the entire file into a list of strings in the behavior unit

Write (astring) output byte string to file

Writelines (alist) is used to write all the strings in the list to the file

File operation:

Attention

The file method read () reads the file with its line terminator

File method Write () does not automatically add a line terminator to the write operation

When implementing a file read or write in a Python program, convert the object to a string using the conversion tool

Pickle Module

Shelve module

6. File Object Properties

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Python v. Python file object