如何创建一个用随机字符串填充列的pandas数据帧？

import pandas as pd
import random
import string

def generate_random_string(length):
    letters = string.ascii_letters
    return ''.join(random.choice(letters) for i in range(length))

df = pd.DataFrame()

num_columns = 5
column_length = 10

for i in range(num_columns):
    column_name = f'Column{i+1}'
    random_strings = [generate_random_string(column_length) for j in range(column_length)]
    df[column_name] = random_strings

print(df)