在pandas dataframe列名中插入列表

Question

I have a dataframe that I initiate like this:

df = pd.DatFrame(columns=('col_A', 'col_B', 'col_C', 'col_D'))

I want to insert a list of column names in this dataframe, but this does not work:

list_col_names = ['aa', 'bb']
df = pd.DatFrame(columns=('col_A', 'col_B', list_col_names, 'col_C', 'col_D'))

I get this error: *** TypeError: unhashable type: 'list'

How do I fix it? I want all the items in list_col_names to become column names in the pandas dataframe

Answer 1

You are effectively passing in ('col_A', 'col_B', ['aa', 'bb'], 'col_C', 'col_D') as an argument; so for example, try df = pd.DataFrame(columns = ['col_A', 'col_B'] + list_col_names + ['col_C', 'col_D']) instead.

You got an error because pandas tried to create a single column from a list ['aa', 'bb'] , which doesn't work.