Reference library

Files & data

Read and write files safely; parse JSON, CSV, and common text formats.

8 matches
Files & data easy

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.

file-metadata pathlib directory
Python
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,
                "exten…
17 0 Open
Files & data easy

How to Group Files by Extension in Python

Group file names by their file extension using a dictionary and pathlib, producing a simple clear mapping for beginners.

pathlib grouping filesystem
Python
from pathlib import Path


def group_data_by_extension(files: list[Path]) -> dict[str, list[str]]:
    """Group file names by their extension."""
    grouped: dict[str, list[str]] = {}
    for file in files:
        ext = file.suffix.lower()
        grouped.setdefault(ext, []).append(file.name)
    return grouped


if…
14 0 Open
Files & data easy

How to Parse XML Attributes into a Flat Dictionary in Python

Parses XML elements and attributes using ElementTree, building a flat dictionary keyed by element attributes.

xml elementtree parsing
Python
import xml.etree.ElementTree as ET

xml_data = """<root>
    <book id="1" category="fiction" price="9.99">
        <title>The Catcher</title>
    </book>
    <book id="2" category="nonfiction" price="12.50">
        <title>Deep Learning</title>
    </book>
</root>"""

def parse_xml_attributes(xml_string):
    root = E…
15 0 Open
Files & data easy

How to Read a JSON File into a Dictionary in Python

Load a JSON file into a Python dictionary using the json.load() function with proper file handling and UTF-8 encoding.

json file-io dictionary
Python
import json
from pathlib import Path

def read_json_file(filepath: str) -> dict:
    """Read a JSON file and return its contents as a dictionary."""
    path = Path(filepath)
    with path.open("r", encoding="utf-8") as f:
        data = json.load(f)
    return data

if __name__ == "__main__":
    # Create a sample JS…
13 0 Open
Files & data easy

How to Split Files by Extension in Python

Group files in a folder by their file extension into a dictionary using pathlib.

pathlib filesystem grouping
Python
from pathlib import Path

def split_files_by_extension(folder_path):
    folder = Path(folder_path)
    files_by_ext = {}

    for file_path in folder.iterdir():
        if file_path.is_file():
            ext = file_path.suffix.lower() or "no_extension"
            files_by_ext.setdefault(ext, []).append(file_path.na…
12 0 Open
Files & data easy

How to Validate a JSON File in Python

A beginner-friendly Python helper that reads a JSON file, catches common errors, and returns a status dictionary.

json validation file-handling
Python
import json
from pathlib import Path

def get_valid_json_data(file_path: str) -> dict:
    file = Path(file_path)
    if not file.exists():
        return {"status": "error", "message": f"File not found: {file_path}"}
    
    try:
        data = json.loads(file.read_text())
    except json.JSONDecodeError as e:
     …
13 0 Open
Files & data easy

How to Write a Dict to a Pretty JSON File with Indent in Python

Serializes a Python dictionary to a readable JSON file using json.dump with indentation and sorted keys, then prints the file contents to stdout.

json files serialization
Python
import json
from pathlib import Path

data = {
    "name": "Python",
    "version": 3.12,
    "features": ["simple", "readable", "powerful"],
    "nested": {"creator": "Guido van Rossum", "year": 1991}
}

output_path = Path("output.json")

with output_path.open("w", encoding="utf-8") as f:
    json.dump(data, f, inden…
14 0 Open
Files & data easy

Parse Fixed Width Data File by Column Slices in Python

Extract fields from fixed-width text by slicing each line at defined column offsets, with a dictionary describing the boundaries.

fixed-width string-slicing parsing
Python
from pathlib import Path


def parse_fixed_width(data: str, slices: dict[str, tuple[int, int]]) -> list[dict[str, str]]:
    lines = data.strip().splitlines()
    records = []
    for line in lines:
        record = {}
        for name, (start, end) in slices.items():
            record[name] = line[start:end].strip()…
13 0 Open

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Files & data — Python code examples

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This page collects files & data snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.