Filesystem
Cement includes a Filesystem Utility Module with helpers for common tasks related to filesystem management.
API References:
Creating and cleaning up temporary directories and files can be tedious, so we created the
fs.Tmp class to make management easy:Example: Temporary Directories and Files
cli
example.py
import os
from cement import fs
# create a tmp object (includes dir and file)
with fs.Tmp() as t:
# do something with a temporary dir
print('Temp Dir: %s' % t.dir)
os.listdir(t.dir)
# do something with a temporary file
print('Temp File: %s' % t.file)
with open(t.file, 'w') as f:
f.write('some data')
$ python example.py
Temp Dir: /var/folders/jm/cr24ncsn1lgdblxm2mvgtdt40000gn/T/tmpwzo8kh89
Temp File: /var/folders/jm/cr24ncsn1lgdblxm2mvgtdt40000gn/T/tmps4s7n8xg
When using the Python
with operator, the temporary directory and file are automatically cleaned up when exiting the block.Creating a
.bak of a directory or file before modifying it is one of the most common tasks when working with the filesystem, but often takes some tedious code to do so without overwriting existing backups. The fs.backup() creates a .bak file, or if it exists .bak.0, .bak.1, .bak.2, etc.Example: Backup Directories and Files
from cement import fs
# create a backup of a file or directory
fs.backup('/path/to/my/file')
Best practice when working with paths is to use
os.path.join() to ensure cross-platform compatibility and also expanding the absolute path to account for things like ~ (user home dir) on Linux. We've created a number of helpers to meld these together for common tasks:Example: Filesystem Paths
from cement import fs
# expand the full absolute path
fs.abspath('./some/relative/path')
fs.abspath('~/some/user/path/')
# join a path while also expanding absolute path
fs.join('~', '.myapp')
fs.join('.', 'some', 'sub-dir')
# join a path and test that it exists
path,exists = fs.join_exists('~', '.myapp')
if exists is True:
# do something with the full absolute path
os.listdir(path)
# ensure a directory exists
fs.ensure_dir_exists('/path/to/some/dir')
# ensure a parent directory exists
fs.ensure_parent_dir_exists('/path/to/parent/child')
Last modified 4yr ago