移除具有与其他列相似的子字符串的列Python

import pandas as pd
import numpy as np

data = {'Column1': ['apple', 'banana', 'orange', 'grape'],
        'Column2': ['apple123', 'banana456', 'orange789', 'grape123'],
        'Column3': ['apple123', 'banana789', 'orange123', 'grape456']}
df = pd.DataFrame(data)

def is_substring(string, columns):
    for col in columns:
        if string in df[col].values:
            return True
    return False

columns_to_remove = []
for col in df.columns:
    if is_substring(df[col].values[0], df.columns[df.columns != col]):
        columns_to_remove.append(col)
df = df.drop(columns_to_remove, axis=1)

print(df)