Reference library

Files & data

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

10 matches
Files & data medium

Create a Python Tool That Generates Professional Excel Dashboards

Generate a professional sales dashboard in an Excel workbook with styled headers, a bar chart, and formatted number cells using the openpyxl library.

openpyxl excel dashboard
Python
import openpyxl
from openpyxl.chart import BarChart, Reference
from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
from openpyxl.utils import get_column_letter

def create_sales_dashboard(workbook_path: str) -> None:
    """Generate a professional sales dashboard in an Excel workbook."""
    wb = op…
49 0 Open
Files & data easy

Export List of Dicts to CSV in Python

Write a list of dictionaries (dataframe-like) to a CSV file with headers using the standard library csv module and verify by reading it back.

csv export dictwriter
Python
import csv

def export_to_csv(data, filename):
    """Export a list of dicts to a CSV file."""
    if not data:
        print("No data to export")
        return
    
    # Get column names from the keys of the first dict
    fieldnames = list(data[0].keys())
    
    with open(filename, 'w', newline='', encoding='utf…
14 0 Open
Files & data easy

Export SQLite Query Results to CSV in Python

Connects to a SQLite database, runs a query, and writes the result rows and column headers to a CSV file using the standard library.

sqlite csv export
Python
import sqlite3
import csv

def export_query_to_csv(db_path, query, csv_path):
    conn = sqlite3.connect(db_path)
    cursor = conn.cursor()
    cursor.execute(query)

    rows = cursor.fetchall()
    column_names = [description[0] for description in cursor.description]

    with open(csv_path, 'w', newline='', encodi…
17 0 Open
Files & data medium

Generate a Monthly Calendar PDF in Python

Create a Python utility that generates a monthly calendar PDF using ReportLab, with weekday headers and day numbers laid out in a grid.

calendar pdf reportlab
Python
from calendar import TextCalendar
from datetime import datetime
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
import os

def generate_monthly_calendar_pdf(year, month, filename="calendar.pdf"):
    cal = TextCalendar()
    days = cal.monthdays2calendar(year, month)
    
    month_name …
1767 0 Open
Files & data easy

How to Convert CSV Column Types While Reading in Python

Read a CSV file and automatically convert column values to int, float, str, or bool based on type suffixes in the header names.

csv type-conversion file-io
Python
import csv
from pathlib import Path
from typing import Any

def read_csv_with_types(filepath: str) -> list[dict[str, Any]]:
    """Read CSV and convert column types based on header suffixes."""
    converters = {
        "int": int,
        "float": float,
        "str": str,
        "bool": lambda v: v.strip().lower(…
11 0 Open
Files & data easy

How to Read Binary File Bytes and Inspect the Header in Python

Read the first bytes of a binary file with pathlib and display them as a hex dump plus an ASCII view to inspect file headers.

binary file-io hex
Python
import pathlib

def inspect_binary_header(filepath: str, num_bytes: int = 16) -> None:
    """Read the first bytes of a binary file and display them as hex and ASCII."""
    path = pathlib.Path(filepath)
    data = path.read_bytes()[:num_bytes]
    
    hex_str = ' '.join(f"{byte:02x}" for byte in data)
    ascii_str …
12 0 Open
Files & data medium

How to Scrape Headlines from a News Website Using Beautiful Soup in Python

Scrape headline text from a news website using requests and Beautiful Soup with a CSS selector.

web scraping beautifulsoup requests
Python
import requests
from bs4 import BeautifulSoup

def scrape_headlines(url: str, selector: str) -> list:
    """
    Scrape headlines from a news website using Beautiful Soup.
    
    Args:
        url: The URL of the news website.
        selector: CSS selector for headline elements.
    
    Returns:
        List of h…
56 0 Open
Files & data easy

Normalize CSV Column Names to snake_case in Python

Convert CSV header names to snake_case using a regular expression and write the updated file in place.

csv regex snake-case
Python
import csv
import re
import sys


def to_snake_case(header):
    header = re.sub(r"(?<=[a-z0-9])(?=[A-Z])", "_", header)
    header = re.sub(r"[^a-zA-Z0-9]+", "_", header).strip("_").lower()
    return header


def normalize_csv_headers(input_path, output_path=None):
    with open(input_path, newline="", encoding="utf…
13 0 Open
Files & data easy

Split CSV Files into Smaller Chunks in Python

Splits a large CSV file into multiple smaller chunk files, preserving the header row in each chunk.

csv file-splitting batch-processing
Python
import csv
import os

def split_csv(input_file, chunk_size=1000, output_prefix="chunk"):
    """Split a large CSV file into smaller chunks."""
    with open(input_file, 'r', newline='') as infile:
        reader = csv.reader(infile)
        header = next(reader)
        
        file_count = 1
        row_count = 0
  …
44 0 Open
Files & data easy

Write CSV file with csv DictWriter in Python

Write a list of dictionaries to a CSV file using Python's csv.DictWriter, including a header row.

csv file-writing dictwriter
Python
import csv
from pathlib import Path

fieldnames = ["name", "city", "age"]
rows = [
    {"name": "Alice", "city": "New York", "age": 30},
    {"name": "Bob", "city": "Los Angeles", "age": 25},
    {"name": "Charlie", "city": "Chicago", "age": 35},
]

path = Path("people.csv")
with path.open("w", newline="") as csvfile:…
16 0 Open

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