12 Read/Write Files

12.1 Pathlib

We often deal with files stored in our computer (or someone else’s, a.k.a. “the Cloud”). The built-in pathlib is very a useful module. In particular, the Path class simplifies a lot the operations we typically do when working with files.

from pathlib import Path

dirname = "./a-new-dir"  # Note: This folder does not yet exist
path = Path(dirname)

path.exists()

False

Let’s create it:

path.mkdir()

path.exists()

True

Notice how the Path instance composes very nicely with the rest of the language. For example, it will automatically concatenate the path with this syntax:

filepath = path/"a-great-file.txt"

filepath

PosixPath('a-new-dir/a-great-file.txt')

filepath.exists()

False

Let’s create it:

filepath.touch()

filepath.exists()

True

This file is still empty, let’s write a message into it:

filepath.write_text("Hello world, this is so much fun!")

A lot just happened:

the file was created
we opened the file
we wrote the text into it
we closed the file
we got back the number of bytes written (33)

So the Path class is abstracting away a lot of work. Pretty handy, I think.

Now let’s read in the content of the file:

filepath.read_text()

'Hello world, this is so much fun!'

Note

The classical way to open/close files is actually using the open function. You can google it if you’re curious, but, for now, let’s run with pathlib.Path.

We can also delete files/directories:

filepath

PosixPath('a-new-dir/a-great-file.txt')

filepath.unlink()  # unlink means remove in this context

filepath.exists()

False

12.2 Files & Directories

When manipulating files we sometimes we want to explicitly distinguish between files and directories. pathlib.Path has a few methods that make our life easier:

current = Path(".")  # dot means current dir

current.is_file()

False

current.is_dir()

True

Tip

Explore the methods of the Path class by creating and object and hitting the Tab key, there are several handy functionalities included.

12.3 Shutil

🚧 Material under construction 🚧