12.1.3 Manipulating pathnames

>>> import os
>>> print(os.path.join('bin', 'utils', 'disktools'))
bin\utils\disktools

>>> import os
>>> print(os.path.join('bin', 'utils', 'disktools'))
bin/utils/disktools

>>> import os
>>> print(os.path.join('mydir\\bin', 'utils\\disktools\\chkdisk'))
mydir\bin\utils\disktools\chkdisk

>>> path1 = os.path.join('mydir', 'bin'); 
>>> path2 = os.path.join('utils', 'disktools', 'chkdisk')
>>> print(os.path.join(path1, path2))
mydir\bin\utils\disktools\chkdisk

>>> import os
>>> print(os.path.split(os.path.join('some','directory', 'path')))
('some\\directory', 'path')

>>> import os
>>> os.path.basename(os.path.join('some', 'directory', 'path.jpg'))
'path.jpg'
>>> os.path.dirname(os.path.join('some', 'directory', 'path.jpg'))
'some\\directory'

>>> os.path.splitext(os.path.join('some', 'directory', 'path.jpg'))
'some/directory/path', '.jpg')

12.1.4 Useful constants and functions

>>> import os
>>> os.name
'nt'

import os
if os.name == 'posix':
    root_dir = "/"
elif os.name == 'nt':
    root_dir = "c:\\"
else:
    print("Don't understand this operating system!")

12.2. Getting information about files

>>> import os
>>> os.path.exists('C:\\Documents and Settings\\vern\\My Documents')
True
>>> os.path.exists('C:\\Documents and Settings\\vern\\My Documents\\Letter.doc')
True
>>> os.path.exists('C:\\Documents and Settings\\vern\\\My Documents\\ljsljkflkjs')
False
>>> os.path.isdir('C:\\Documents and Settings\\vern\\My Documents')
True
>>> 	os.path.isfile('C:\\Documents and Settings\\vern\\My Documents')
False
>>> os.path.isdir('C:\\Documents and Settings\\vern\\My Documents
\\Letter.doc')
False
>>> os.path.isfile('C:\\Documents and Settings\\vern\\My Documents\\Letter.doc')
True

12.3 More file system operations

>>> os.chdir(os.path.join('c:','my documents', 'tmp'))
>>> os.listdir(os.curdir)
['book1.doc.tmp', 'a.tmp', '1.tmp', '7.tmp', '9.tmp', 'registry.bkp']

>>> import glob
>>> glob.glob("*")
['book1.doc.tmp', 'a.tmp', '1.tmp', '7.tmp', '9.tmp', 'registry.bkp']
>>> glob.glob("*bkp")
['registry.bkp']
>>> glob.glob("?.tmp")
['a.tmp', '1.tmp', '7.tmp', '9.tmp']
>>> glob.glob("[0-9].tmp")
['1.tmp', '7.tmp', '9.tmp']

>>> os.rename('registry.bkp', 'registry.bkp.old')
>>> os.listdir(os.curdir)
['book1.doc.tmp', 'a.tmp', '1.tmp', '7.tmp', '9.tmp', 'registry.bkp.old']

>>> os.makedirs('mydir')
>>> os.listdir(os.curdir)
['mydir', 'a.tmp', '1.tmp', '7.tmp', '9.tmp', 'registry.bkp.old']
>>> os.path.isdir('mydir')
True

>>> os.rmdir('mydir')
>>> os.listdir(os.curdir)
['a.tmp', '1.tmp', '7.tmp', '9.tmp', 'registry.bkp.old']

12.4 Processing a directory subtree

import os
for root, dirs, files in os.walk(os.curdir):
    print(root, "has",len(files), "files")
    if ".git" in dirs:     
        dirs.remove(".git")