Working with pathlib

Note

Source: Python-specific — no direct equivalent in the C# edition. C# uses the System.IO.Directory and System.IO.File classes; Python’s pathlib module provides an object-oriented interface that combines both into a single Path type.

The pathlib module, introduced in Python 3.4, represents file system paths as objects rather than plain strings. This makes path manipulation readable and cross-platform.

Creating Path Objects

from pathlib import Path

p = Path("data/numbers.txt")   # relative path
q = Path("/Users/alice/notes") # absolute path
r = Path.cwd() / "output.txt"  # build from current directory

Path Attributes

A Path object exposes the components of a path as attributes:

p = Path("reports/2024/summary.csv")

print(p.name)    # filename with extension
print(p.stem)    # filename without extension
print(p.suffix)  # extension including the dot
print(p.parent)  # directory containing the file

Output:

summary.csv
summary
.csv
reports/2024

Checking Existence

p = Path("data.txt")

if p.exists():
    print("found")
if p.is_file():
    print("it is a regular file")
if p.is_dir():
    print("it is a directory")

Listing Directory Contents

Path.iterdir() yields all entries (files and subdirectories) in a directory:

for entry in Path(".").iterdir():
    print(entry.name)

Path.glob(pattern) filters by a wildcard pattern:

for csv_file in Path("data").glob("*.csv"):
    print(csv_file)

Output (example):

data/sales.csv
data/inventory.csv

Reading and Writing via Path

For simple cases, Path objects have read_text() and write_text() convenience methods that open, operate, and close the file automatically:

content = Path("notes.txt").read_text()
Path("copy.txt").write_text(content)

For more control — reading line by line, appending, or writing with formatted output — use open() as described in Reading Files and Writing Files.