如果我理解正确，则应填写作业：
>>> import numpy as np>>> import pandas as pd>>> df = pd.Dataframe({"A": [1,2,3], "B": [2,3,4]})>>> df A B0 1 21 2 32 3 4>>> df["C"] = "">>> df["D"] = np.nan>>> df A B C D0 1 2 NaN1 2 3 NaN2 3 4 NaN
如果我理解正确，则应填写作业：
>>> import numpy as np>>> import pandas as pd>>> df = pd.Dataframe({"A": [1,2,3], "B": [2,3,4]})>>> df A B0 1 21 2 32 3 4>>> df["C"] = "">>> df["D"] = np.nan>>> df A B C D0 1 2 NaN1 2 3 NaN2 3 4 NaN名师互学网 版权所有 (c)2021-2022 ICP备案号：晋ICP备2021003244-6号
