Getting Started with Pathlib

Iyanuoluwa Ajao — Fri, 30 Nov 2018 00:12:32 +0000

Introduction

This tutorial will guide you on how to use the Pathlib module for working with filesystem paths, the benefits, and understand the problem it solves since the Python standard library already contains os.path.

How is it Better than os.path

os.path was the only way to work with filesystem paths, but it had some limitations. To perform certain tasks, you
have to import from other standard library modules. For instance, suppose you want to list the files ending with .txt
in a directory, os.path is not enough.

Using os.path, you will do this:

import os
import glob

list(glob(os.path.join('posts', '*.md')))

Using pathlib, you will do this:

from pathlib import Path

list(Path('posts').glob('*.md'))

From the first example that makes use of os.path, there was the need to import glob. But with pathlib, most of the functionality found in other modules are now in one place.

Getting Started

from pathlib import Path

According to the standard library, Path instantiates a concrete path for the platform your code is running on.
This basically means that Path class figures out the necessary path separator that is required for the platform
your code is running on.

NB: Windows uses a backslash as a path separator while unix based systems use the forward slash.

There are other classes that can be used, such as the WindowsPath and PosixPath

Using Path classmethods

Path.home()

PosixPath('/home/ashiri')


Path.cwd()

PosixPath('/home/ashiri/iyanuashiri/content/posts')

The Path class provides us with two classmethods. The home classmethod returns a home directory path object while the
cwd classmethod returns the current working directory path object

Creating Path object

p = Path.home() / 'iyanu'

PosixPath('/home/ashiri/iyanu')

This code snippet creates a path object that can be used in your Python code, but the directory already exist
for the code to do something. In the next two examples, we will show how to create a new directory and a new file from
your Python code.

Create a New Directory

p = Path.home() / 'folder_name'
p.mkdir()

In the code snippet above, we create a path object called p and use the instance method mkdir.

Create a New File

p = Path.home() / 'folder_name'
p.mkdir()

r = p / 'file_name.txt'

r.touch()

In this code snippet, we start by creating a path object called p, then use the mkdir() instance method.
The next thing is create another path object called r and use the instance method touch().

The mkdir(exist_ok=True) method can take in an argument. This prevents a FileExistsError from being raised.

Opening a File in a Path

There is an open instance method that works like the builtin open function. So we can do something
like this:

with r.open as file:
    file.readline

In conclusion

There is more than can be learnt on the pathlib documentation page, which can be found here

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