Joining two dataset with different weights

Question

I'm trying to join two dataframes, one containing signal events and one containing background events. But I want the signals to be counted let's say 10 times more. Is there a better way to do it than using:

total = background
for i in range (0, 10):
  total = total.append(signals)

Each column of the dataframe is associated with a variable, like energy or momentum etc. It's fine even if I manage to merge only two columns.

It would also be great to somewhat label the signals event once they are stored in total, like adding another column with values (signal = 1, bkg = 0)

I hope my question is not too confusing, it's my first time here