Python读取CSV提取Virginia数据写入后输出文件为空问题排查

• 写入参数错误：代码中writer.writerow(row)传入的row是行索引整数，并非拆分后的行内容列表，正确参数应为contents[row]。
• 逻辑冗余：内层for word in range(len(contents[row]))循环无实际作用，匹配逻辑未使用word变量，不仅拖慢运行效率，匹配成功后还会重复写入同一行。
• 处理方式不规范：直接用split(',')拆分CSV行，遇到字段内含逗号的场景会拆分错误，使用csv.reader处理输入更稳妥。
• 表头丢失：现有逻辑未保留原CSV的表头，生成的文件没有字段说明。

import csv

input_file = 'all.csv'
output_file = 'Virginia.csv'
state = 'Virginia'

def extract_records_for_state(input_file, output_file, state):
    with open(input_file, 'r', newline='', encoding='utf-8') as infile:
        reader = csv.reader(infile)
        # 读取表头
        header = next(reader)
        with open(output_file, 'w', newline='', encoding='utf-8') as outfile:
            writer = csv.writer(outfile)
            # 写入表头
            writer.writerow(header)
            for row in reader:
                # 第三列为州名，匹配成功则写入
                if len(row) >= 3 and row[2] == state:
                    writer.writerow(row)

extract_records_for_state(input_file, output_file, state)

内容的提问来源于stack exchange，提问作者Geraldo