python CSV编写器，panda，如何使用同一文本文件在两列中编写CSV文件只有一个库

假设文本文件包含以下元素：

A
B
C
D 

我想使用python将这些元素写入CSV文件，如下所示：

A,A
A,B
A,C
A,D
B,A
B,B
B,C
B,D
...

我尝试用csv格式编写文本，其中包含如下乘法数据：

import csv

with open(r'C:\Users\soso-\Desktop\SVM\DataSet\drug_list.txt') as f:
    with open('integrated_x.csv', 'w') as out_file:
        for line in f:
            for x in range(548):
                out_file.write(f"{line.strip()}\n")
f.close()
out_file.close()

输出：

A
A
A
A
B
B
B
....

然后在其他csv文件中添加csv文件的新列，如下所示：

with open(r'C:\Users\soso-\Desktop\SVM\DataSet\drug_list.txt') as f:
    with open(r'integrated_x.csv') as read_obj, \
            open('integrated_x12.csv', 'w', newline='') as write_obj:
    # Create a csv.reader object from the input file object
                csv_reader = csv.reader(read_obj)
    # Create a csv.writer object from the output file object
                csv_writer = csv.writer(write_obj)
        
    # Read each row of the input csv file as list
                for row in csv_reader:
                    for line in f:
        # Append the default text in the row / list
                        row.append(line)
        # Add the updated row / list to the output file
                        csv_writer.writerow(row)

输出：

A,"A"
A,"A,B"
A,"A,B,C"

因此，输出并不像预期的那样，它将列附加为列表并复制前一行。我如何修复它？