下記はどうですか?
df = pd.DataFrame({'a':[1,2,3],'b':[2,3,4]})
df1 = pd.DataFrame({'c':[3,4,5],'d':[4,5,6]})
df = df1.copy()
df.columns=[0,1]
#df = df.rename(columns={'c':0,'d':1})
print("出力結果")
print(df)
print("----------------")
print(df1)
参考
https://qiita.com/analytics-hiro/items/e8fdf8652869817851cd
Like!