pandas_math.py

import pandas as pd
import numpy as np

def create_empty_dataframe(new_column_list, num_rows):
    
       """
       Creates a new dataframe filled with zeroes from a specified 
       list and number of rows. 

        Args:
            new_col_list (object): List of column names. 
            num_rows (int): Number of rows you want the new table to have.

        Returns:
            df: returns a pandas dataframe with specific column 
                names and number of rows. 
       """
        
    col_list = new_column_list
    num_cols = len(new_column_list)
    fill_with_zeroes = np.zeros(shape=(num_rows, num_cols))
    new_df = pd.DataFrame(fill_with_zeroes, columns=[col_list])
    
    return new_df
  

test_pandas_math.py

import pytest

from mypackage_two.pandas_math import create_empty_dataframe

class TestCreateEmptyDataframe(object):

    def test_on_create_empty_dataframe(self):

        actual = len(create_empty_dataframe(['foo', 'bar'], 20))
        expected = 20
        assert actual == expected