无法将列插入新创建的 dataframe（Python - Pandas）

Question

Let df be a dataframe. I'm trying to place the column a into another dataframe called df2

 df2.insert(1,'a',df['a'])

Everything goes well when df2 is loaded from excel:

df2 = pandas.read_excel(filepath)

Yet, when I create df2 from scratch, there's an error:

df2 = pandas.DataFrame

The error reads:

insert() missing 1 required positional argument: 'value'

What is going on?

Answer 1

The correct way is that you give a value in pd.DataFrame(abc) now here abc can be a matrix or dictionary

you can use this too:

pd.DataFrame(df[['a']])