Python CSV逻辑

我正在尝试创建一个python程序，测试csv中的某些单元格是否具有值4，如果它们具有值4，则应将整行写入名为grade4.csv的csv文件。这是我目前掌握的代码：

import csv
with open('register-all-subs-2020-05-31.csv') as csvDataFile:
      csvReader = csv.reader(csvDataFile)
      data = [row for row in csv.reader(csvDataFile)]
      r=0
      c=0
      for r in range(33):
           for c in range(7):
                 print(data[r][c])

---

但是，我不知道如何测试单元格中的某些值并将行写入csv。如果有人能帮上忙，那就太好了。

试试这个，根据你的目的稍微修改一下：

def check_four(row):
    for cell in row:
        if "4" in cell:
            return True
    return False


def main():
    with open("file.csv","r") as f:
        data = f.read()
    rows = data.split(",")
    new_rows = []   
    for row in rows:
        if check_four(row):
            new_rows.append(row)
    new_data = ','.join(new_rows)
    with open("grade4.csv","w") as f:
        f.write(new_data)

if __name__ == "__main__":
    main()