How to select subdataframe based on multiple column

I have a dataframe that contains a large number of columns. I classified these columns and got three lists, each of which contains some column names. For instance:

l1 = ['Year','Day','Month']

l2 = ['A1','A2','A3',...,'A50']

l3 = ['B1','B2','B3',...,'B50']

I want to get a new dataframe that only contains columns within the above three lists.

I tried

df_new = df[l1]   df[l2]   df[l3]

But the result is not correct because the data types are different. I don't think merge, join, or concatenate is necessary because the length of columns is the same and they don't have any common column name. Could you help me with a handy way to do this?

CodePudding user response：

You would need to add the lists first to get all the column names in a single list and then use it to get part of the dataframe. Try:

df_new = df[[l1   l2   l3]]