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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…
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