Convert File Data to a Dictionary in Python

This function scans a directory and converts each file's metadata (name, size, extension) into a structured dictionary for easy access.

Easy Python 3.9+ Aug 9, 2026 Files & data 15 views 0 copies

file-metadata pathlib directory dictionary files

Python code

27 lines

Python 3.9+

from pathlib import Path

def convert_files_data(directory: str) -> dict:
    data = {}
    base = Path(directory)
    if not base.exists():
        return data
    for file in base.iterdir():
        if file.is_file():
            data[file.name] = {
                "size": file.stat().st_size,
                "extension": file.suffix or "none"
            }
    return data

if __name__ == "__main__":
    import tempfile, os
    with tempfile.TemporaryDirectory() as tmpdir:
        for name, content in [("notes.txt", "hello"), ("script.py", "print(1)"), ("image.png", b"\x89PNG")]:
            p = Path(tmpdir) / name
            if isinstance(content, bytes):
                p.write_bytes(content)
            else:
                p.write_text(content)
        result = convert_files_data(tmpdir)
        for filename, info in sorted(result.items()):
            print(f"{filename}: {info['size']} bytes, .{info['extension']}")

Output

stdout

notes.txt: 5 bytes, .txt
script.py: 9 bytes, .py

How it works

The Path.iterdir() method yields all entries in the directory, and file.is_file() filters out subdirectories. The file.stat() call retrieves filesystem metadata, and st_size provides the byte size. The suffix property returns the file extension (e.g., '.txt'), or an empty string if none exists, which we convert to 'none' for clarity. Using Path from the standard library keeps the implementation cross-platform and dependency-free.

Common mistakes

Forgetting that `iterdir()` also returns subdirectories — must filter with `is_file()`
Assuming the directory exists; always check with `exists()` or catch `FileNotFoundError`
Using `os.listdir()` text names instead of `Path` objects, which makes extension handling awkward

Variations

Use `os.scandir()` with `entry.is_file()` for a lower-level alternative
Return a list of dictionaries or a `defaultdict` if you need repeated keys

Real-world use cases

Building a directory inventory report for a backup or migration tool.
Feeding file metadata into a data pipeline for analytics or monitoring.
Creating a lightweight index of uploaded attachments in a web app.

Convert File Data to a Dictionary in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

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