Automate Multiple Sheet Excel Reporting - Python Automation

the following code runs without any errors

import pandas as pdimport numpy as npimport matplotlib.pyplot as plt
excel_file_1 = 'shift-data.xlsx'excel_file_2 = 'third-shift-data.xlsx'
df_first_shift = pd.read_excel(excel_file_1, sheet_name='first')df_second_shift = pd.read_excel(excel_file_1, sheet_name='second')df_third_shift = pd.read_excel(excel_file_2)
print(df_first_shift)print(df_first_shift['Product'])
df_all = pd.concat([df_first_shift, df_second_shift, df_third_shift])print(df_all)
pivot = df_all.groupby(['Shift']).mean()shift_productivity = pivot.loc[:,"Production Run Time (Min)":"Products Produced (Units)"]
print(shift_productivity)
#shift_productivity.plot(kind='bar')#plt.show()
df_all.to_excel("output.xlsx")