CSV Files — Reading & Writing Tabular Data

Built-in csv module:

import csv

# Reading
with open("data.csv", "r") as f:
    reader = csv.reader(f)
    for row in reader:
        print(row)  # row is a list

# Reading with headers as dict
with open("data.csv", "r") as f:
    reader = csv.DictReader(f)
    for row in reader:
        print(row["name"], row["age"])

Writing:

data = [["Alice", 30], ["Bob", 25]]

with open("output.csv", "w", newline="") as f:
    writer = csv.writer(f)
    writer.writerow(["name", "age"])  # header
    writer.writerows(data)

# Dict writer
with open("output.csv", "w", newline="") as f:
    fields = ["name", "age"]
    writer = csv.DictWriter(f, fieldnames=fields)
    writer.writeheader()
    writer.writerow({"name": "Alice", "age": 30})

With pandas (easier for large files):

df = pd.read_csv("data.csv")
df.to_csv("output.csv", index=False)

Reference:

Wikipedia: CSV

https://en.wikipedia.org/wiki/Comma-separated_values