Spotfire Python data function, how to reduce the table loading time?

Question

Here is the example code in my Python data function:

import warnings
warnings.filterwarnings("ignore")
import pandas as pd
import io
import sys

pd_temp=pdtable
str1="Hello"

pdtable is input parameter.

str1 is output parameter.

When the size of the input table is over 500,000 rows, the loading time of the table is very slow. It needs about 7 minutes. Is there a way to reduce the loading time?

Can the data function read sbdf files in the library?

addthe screenshot below