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Use pathlib for file paths

pathlib is the standard library tool for working with file system paths. It usually produces clearer code than building path strings by hand, and it handles path operations in a way that works across operating systems.

Why this matters​

Raw string paths tend to collect small mistakes:

config_path = "config/" + filename + ".json"

This style is easy to get wrong when:

  • a slash is missing or duplicated
  • the code runs on another operating system
  • you need the parent directory, file name, or suffix

pathlib gives you path objects with useful methods instead of making you manipulate strings manually.

Prefer Path objects​

from pathlib import Path

filename = "settings"
config_path = Path("config") / f"{filename}.json"

print(config_path)

Output:

config/settings.json

The / operator joins path segments in a readable way, and the result is still a path object that can be inspected or reused.

Common tasks become easier​

pathlib keeps file operations and path operations close together:

from pathlib import Path

path = Path("data") / "report.txt"

print(path.name)
print(path.suffix)
print(path.parent)

Output:

report.txt
.txt
data

That is usually easier to read than splitting strings and joining them again later.

When to use strings anyway​

Some libraries still expect plain strings. In those cases, you can convert a path object with str(path).

note

Many modern libraries accept Path objects directly, so it is often worth trying that first.

Rules of thumb​

  • Reach for pathlib before manual path-string building.
  • Use Path(...) / "child" to join path segments.
  • Keep values as path objects until a library truly needs a string.
  • Use path methods such as .name, .suffix, and .parent instead of string slicing.