CSV モジュールを使用して CSV ファイルの特定の列からデータを抽出するにはどうすればよいですか?

Extracting Data from Specific Columns in a CSV File with the CSV Module

In working with CSV files, it is often necessary to extract data from specific columns only. To achieve this using the CSV module, it is important to understand how the library handles data retrieval.

In the provided code sample, the attempt to access specific columns is through row[i] syntax, where i represents the column number. However, the result is not as expected due to an incorrect approach.

The correct method is to include the print statement within the for loop. The following corrected code demonstrates this:

import csv

included_cols = [1, 2, 6, 7]
with open("csv_file.csv") as csvfile:
    reader = csv.reader(csvfile, delimiter=",")
    for row in reader:
        content = list(row[i] for i in included_cols)
        print(content)  # Include the print statement within the loop to display each row

Now, the modified code will print out the values from the desired columns for each row.

However, it's worth mentioning an alternative approach using the pandas library, which simplifies the handling of CSV files. With pandas, you can easily read a CSV file and extract specific columns into variables:

import pandas as pd

df = pd.read_csv("csv_file.csv")
names = df["Name"]  # Use df['column_name'] to extract a specific column into a variable

The pandas library provides a versatile set of tools for working with structured data, making it a recommended choice for handling CSV files effectively.

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