pyhont module os (continuously updated ........)

1.os.path.exists(path)

Determine whether the file path path exists, there is a return Ture, there is no return False.

Example:

SYS Import, the shutil, os 
# pick second parameter 
path = the sys.argv [. 1] 
# to make the os path determination module, returns False or True 
In Flag = os.path.exists (path) 
IF In Flag: 
    # use shutil module deletes files 
    shutil.rmtree (path) 
the else: 
    Print ( 'does not exist')

2.os.path.abspath()

Returns the absolute path of a file.

Example:

import os

path = os.path.abspath('day04_task.py')
print(path)

3.os.stat(path).size

Returns the size of the file to bit units.

OS Import 
# 1. read the file size (bytes) 
FILE_SIZE the os.stat = ( '20190409_192149.mp4'). the st_size 
# 2. little by little to read the file 
read_size = 0 
with Open ( '20190409_192149.mp4', = MODE 'RB') AS F1, Open ( 'a.mp4', MODE = 'WB') AS f2: 
    the while read_size <FILE_SIZE: 
        the chunk = f1.read (1024) # of bytes 1024 to read the maximum 
        f2 .write (the chunk) 
        read_size + = len (the chunk) 
        Val = int (read_size / FILE_SIZE * 100) 
        Print ( '% S %% \ R & lt'% Val, End = '')

4.os.path.join

Stitching path, stitching together the two paths, and the different splicing can be returned depending on the operating system.

import os

Add r # path before, so that failure of the escape character

path = r'd:\test'

path = os.path.join(path,'1.txt')

print(path)

5.os.listdir, to view a directory of all the files [first floor]

import os
result = os.listdir(r'D:\code\s21day14')
for path in result:
    print(path)

6.os.walk, to view a directory of all the files [all levels]

os Import 
the Result = os.walk (r'D: \ code \ s21day14 ') 
for A, b, c in the Result: 
    # A, are viewing the directory b, files in this directory folder c, files in this directory 
    for C in Item: 
        path the os.path.join = (A, Item) 
        Print (path)