Python Pathlib Module
For a deep dive into practical file system operations, check out our blog post: 10 Essential File System Operations Every Developer Should Know.
The pathlib module was added in Python 3.4, offering an object-oriented way to handle file system paths.
Pathlib vs OS Module
pathlib provides a lot more functionality than the ones from os and listed here, like getting file name, getting file extension, reading/writing a file without manually opening it, etc. See the official documentation if you intend to know more.
For a more in-depth look at both, see the File and directory Paths page.
Linux and Windows Paths
On Windows, paths are written using backslashes (\) as the separator between folder names. On Unix based operating system such as macOS, Linux, and BSDs, the forward slash (/) is used as the path separator. Joining paths can be a headache if your code needs to work on different platforms.
Fortunately, Python provides us with pathlib.Path.joinpath to easily handle this.
from pathlib import Path
# Join path components
print(Path('usr').joinpath('bin').joinpath('spam'))
usr/bin/spam
pathlib also provides a shortcut to joinpath using the / operator:
from pathlib import Path
# Use / operator to join paths
print(Path('usr') / 'bin' / 'spam')
usr/bin/spam
Joining paths is helpful if you need to create different file paths under the same directory.
my_files = ['accounts.txt', 'details.csv', 'invite.docx']
# Get user's home directory
home = Path.home()
# Join each filename with home directory
for filename in my_files:
print(home / filename)
/home/labex/project/accounts.txt
/home/labex/project/details.csv
/home/labex/project/invite.docx
The current working directory
from pathlib import Path
from os import chdir
# Get current working directory
print(Path.cwd())
/home/labex/project
# Change directory using os module
chdir('/usr/lib/python3.10')
# Verify current directory
print(Path.cwd())
/usr/lib/python3.10
Creating new folders
from pathlib import Path
cwd = Path.cwd()
# Create directory (will fail if parent directories don't exist)
(cwd / 'delicious' / 'walnut' / 'waffles').mkdir()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.10/pathlib.py", line 1226, in mkdir
self._accessor.mkdir(self, mode)
File "/usr/lib/python3.10/pathlib.py", line 387, in wrapped
return strfunc(str(pathobj), *args)
FileNotFoundError: [Errno 2] No such file or directory: '/home/labex/project/delicious/walnut/waffles'
The reason of this error is that the ‘delicious’ directory does not exist, so we cannot make the ‘walnut’ and the ‘waffles’ directories under it. To fix this, do:
from pathlib import Path
cwd = Path.cwd()
# Create directory with all parent directories
(cwd / 'delicious' / 'walnut' / 'waffles').mkdir(parents=True)
Absolute vs. Relative paths
There are two ways to specify a file path.
- An absolute path, which always begins with the root folder
- A relative path, which is relative to the program’s current working directory
There are also the dot (.) and dot-dot (..) folders. These are not real folders, but special names that can be used in a path. A single period (“dot”) for a folder name is shorthand for “this directory.” Two periods (“dot-dot”) means “the parent folder.”
Handling Absolute paths
To see if a path is an absolute path:
from pathlib import Path
# Check if path is absolute
Path('/').is_absolute()
True
# Relative paths return False
Path('..').is_absolute()
False
You can also extract an absolute path:
from pathlib import Path
# Get current directory
print(Path.cwd())
/home/labex/project
# Resolve relative path to absolute path
print(Path('..').resolve())
/home
Handling Relative paths
You can get a relative path from a starting path to another path.
from pathlib import Path
# Get relative path from base path
print(Path('/etc/passwd').relative_to('/'))
etc/passwd
Path and File validity
Checking if a file/directory exists
from pathlib import Path
# Check if path exists
Path('.').exists()
True
Path('setup.py').exists()
True
Path('/etc').exists()
True
Path('nonexistentfile').exists()
False
Checking if a path is a file
from pathlib import Path
# Check if path is a file
Path('setup.py').is_file()
True
Path('/home').is_file()
False
Path('nonexistentfile').is_file()
False
Checking if a path is a directory
from pathlib import Path
# Check if path is a directory
Path('/').is_dir()
True
Path('setup.py').is_dir()
False
Path('/spam').is_dir()
False
Getting a file’s size in bytes
from pathlib import Path
# Get file statistics
stat = Path('/bin/python3.10').stat()
print(stat) # stat contains some other information about the file as well
os.stat_result(st_mode=33261, st_ino=141087, st_dev=2051, st_nlink=2, st_uid=0,
--snip--
st_gid=0, st_size=10024, st_atime=1517725562, st_mtime=1515119809, st_ctime=1517261276)
# Access file size from stat object
print(stat.st_size) # size in bytes
10024
Listing directories
from pathlib import Path
# Iterate through directory contents
for f in Path('/usr/bin').iterdir():
print(f)
...
/usr/bin/tiff2rgba
/usr/bin/iconv
/usr/bin/ldd
/usr/bin/cache_restore
/usr/bin/udiskie
/usr/bin/unix2dos
/usr/bin/t1reencode
/usr/bin/epstopdf
/usr/bin/idle3
...
Directory file sizes
WARNING
Directories themselves also have a size! So, you might want to check for whether a path is a file or directory using the methods in the methods discussed in the above section.
from pathlib import Path
# Calculate total size of all files in directory
total_size = 0
for sub_path in Path('/usr/bin').iterdir():
total_size += sub_path.stat().st_size
print(total_size)
1903178911
Deleting files and folders
Calling
Path.unlink()will delete the file at path.Calling
Path.rmdir()will delete the folder at path. This folder must be empty of any files or folders.