Python os library

Access OS interfaces

import os
import shutil
from os import path
from shutil import make_archive
from zipfile import ZipFile

# make a duplicate of an existing file
if path.exists ("w1.txt"):
    # get the path to the file in the current directory
    src = path.realpath ("w1.txt")

    # separate the path part from the filename
    fpath, fname = path.split (src) ## :h :t
    print ( "path:", fpath )
    print ( "file:", fname )

    # let's make a backup copy by appending "bak" to the name
    dst = src + '.bak'
    # now use th eshell to make a copy of the file
    shutil.copy (src,dst)

    # copy over the permissions, modification times, and other info
    shutil.copystat (src,dst)

    # rename the original file
    os.rename ("w1.txt", "new.txt")

    # common use
    os.getcwd()
    os.chdir()
    os.remove('file_to_remove.txt')

Create Archive Zip File

    # now put things into a ZIP archive
    fpath, fname = path.split (src) ## :h :t
    shutil.make_archive ("archive", "zip", fpath)

    # more fine_grained constrol over ZIP files
    with ZipFile ("w1.zip", "w") as newzip:
        newzip.write ("new.txt")
        newzip.write ("w1.txt.bak")

    os.system( "/bin/cp w1.txt.bak w1.txt" )

Find out OS system

import os
print (os.name) ## always posix for linux, windows or OS X
import platform
platform.platform()

os.path

import os.path
os.path.join ('path_name', 'sub_path', 'file_name')
>>> 'path_name/sub_path/file_name'
## on window system
os.path.join ('c:','path_name', 'sub_path', 'file_name')
>>> 'path_name\sub_path\file_name'
os.path.exists ('path_or_file_name')
os.path.isfile ('path_or_file_name')
os.path.isdir  ('path_or_file_name')
os.path.islink ('path_or_file_name')

os.popen

import os
filename = 'book.txt'
cmd = 'ls '+ filename
fp = os.popen( cmd )
res = fp.read()
stat = fp.close()