Combine existing functions to make a final dataframe

Hi Experts,

I have a python code with a couple of functions. I urgently need the following:
1.) Combine relevant functions in the code to make a final dataframe.
Function_final(Historical_Data) = final_df
2.) Create a similar funtion to transform a future data to contain same columns as X_test
Function_upcoming(upcoming_data) = X_test_new
3.) Apply an existing highest accuracy model to predict X_test_new

N/B: I already have a code that does the following:
1.) Download historical data
2.) Functions that transform the historical data to final data by cleaning up
3.) Prediction models
4.) Upcoming data.

So the major task here is to predict upcoming data