比较两个文件中的第一列，如果匹配:更新最后一列变量，否则:将行追加到第二个文件

# 导入所需的模块
import csv

# 定义两个文件的路径
file1_path = "file1.csv"
file2_path = "file2.csv"

# 定义一个字典用于存储第一列的值和最后一列的变量
data_dict = {}

# 读取第一个文件并将第一列的值和最后一列的变量存储到字典中
with open(file1_path, 'r') as file1:
    reader = csv.reader(file1)
    for row in reader:
        data_dict[row[0]] = row[-1]

# 打开第二个文件，比较第一列的值并更新最后一列的变量或追加行
with open(file2_path, 'r') as file2:
    reader = csv.reader(file2)
    rows_to_append = []
    for row in reader:
        if row[0] in data_dict:
            row[-1] = data_dict[row[0]]
        else:
            rows_to_append.append(row)

# 将追加的行写入第二个文件
with open(file2_path, 'a') as file2:
    writer = csv.writer(file2)
    writer.writerows(rows_to_append)