File manipulation with os module in python

import os

File manipulation

# Create some file
touch foo.txt
echo Hello > foo.txt
cat foo.txt

Hello

# rename file
os.rename('foo.txt','bar.txt')
cat bar.txt

Hello

# remove file
os.remove('bar.txt')

Change directory

# current dir
print os.getcwd() # current working directory

/Users/yongle/OMOOC2py/cheat

# go down
os.chdir('img')
print os.getcwd()

# go back up
os.chdir(os.pardir) # or simply os.chdir('..')
print os.getcwd()

/Users/yongle/OMOOC2py/cheat/img
/Users/yongle/OMOOC2py/cheat

List all `listdir`

# listdir
# touch a.txt b.txt
for file in os.listdir('.'):
    # os.listdir() return a list
    if file.endswith('.txt'):
        print file

a.txt
b.txt

Walk `os.walk`

os.chdir('doc')

# Directory tree generator.
# For each dir in the dir tree rooted at top (including top
# itself, but excluding '.' and '..'), yields a 3-tuple
# dirpath, dirnames, filenames
for dirpath, dirnames, filenames in os.walk('.'):
    print dirnames
    print filenames
    break # only one level needed, or just use listdir

['folder1', 'folder2']
['.DS_Store', 'a.txt', 'b.txt']

Add or remove directory

Single level

# make a dir, one level, no duplication allowed
os.mkdir('test')

# remove a dir, one level, not empty will raise OSError
os.rmdir('test') 

Mulitiple level

# make dirs, multipul level
os.makedirs('test/mulitiple/levels')

# remove all empty directories above it, ensure empty
os.removedirs('test/mulitiple/levels')

Non empty directory

# remove non empty dir, ust a new module shutil.rmtree
# copy function is also useful
import shutil

# copy a.txt to backup folder
# or just shutil.copy('a.txt','backup/')
# use shutil.copytree to copy a folder like cp -r
os.mkdir('backup')
shutil.copy('a.txt',os.path.join('backup','a_backup.txt'))

# remove non empty folder
shutil.rmtree('backup/')

os.path module

# is a dir or not
print(os.path.isdir('img'))
print(os.path.isdir('a.txt'))

True
False

# is a file or not
print(os.path.isfile('img'))
print(os.path.isfile('a.txt'))

False
True

# determine the presence of path(a file or dir); os.path.lexists?
print(os.path.exists('img'))
print(os.path.exists('a.txt'))
print(os.path.exists('none_exist.txt'))

True
True
False

# Join two or more pathname components, inserting '/' as needed.
# If any component is an absolute path, 
# all previous path components will be discarded.
print(os.path.join('/Users','john'))
print(os.path.join('/Users','/john'))
print(os.path.join('/Users','john','a.txt'))

/Users/john
/john
/Users/john/a.txt

# split a pathname. Returns "(head, tail)" 
# where "tail" is everything after the final slash.
os.path.split('/Users/john/a.txt')

('/Users/john', 'a.txt')

# split the extension from a pathname
os.path.splitext('/Users/john/a.txt')

('/Users/john/a', '.txt')

# determine the size of a path(file or dir)
os.path.getsize('a.txt')

AI 2

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Bootstrap 1

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CSS 2

Cloud 3

Code 1

Crawler 1

DNS 1

Database 17

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Design 16

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Javascript 4

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MacOS 2

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Mobile 1

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NAS 1

Network 11

NeuralNetwork 10

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OS 8

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Python 15

RESTful 1

Rails 9

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Ruby 6

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php 1

File manipulation with os module in python

File manipulation

Change directory

List all listdir

Walk os.walk

Add or remove directory

Single level

Mulitiple level

Non empty directory

os.path module

List all `listdir`

Walk `os.walk`