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How to Filter CSV Rows by Column Value in Python

Filter CSV rows based on a column value condition using the standard csv module and a lambda function.

csv filter file-io
Python
import csv

def filter_csv(input_file, output_file, column, condition):
    with open(input_file, newline='', encoding='utf-8') as infile, \
         open(output_file, 'w', newline='', encoding='utf-8') as outfile:
        reader = csv.DictReader(infile)
        fieldnames = reader.fieldnames
        writer = csv.Dict…
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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.