Does someone knows why is executing both the If and ELSE statement? Please check my python codes

Hello Y'all..
Hope someone can #help with this question:
I'm plotting a pandas dataframe, where I created a try / except block to create a PDF file. So, if the IF conditional period_fails is not empty, the ELSE statement runs and create a pdf, no problem with that.  if the IF conditional period_fail is empty it raise a ValueError and execute the except ValueError block, great..., but for some reason, still executing the else statement and creating an empty PDF.
Does someone knows why is executing both the If and ELSE statement?
 

print(count) # datafrma to be plotted



            -F

2018-09-03  19

2018-09-04   8

2018-12-07   6



print(count.dtypes)

-F    int64

dtype: object

#------------------------

try:

    with PdfPages(os.path.join(my_out_path, ("{0}_{1}" + ".pdf").format(fname, last_month))) as export_pdf:

        if period_fail.empty:

			raise ValueError

        else:

            count.plot(kind='bar', color='red', legend=None, title='Date / Count')

            plt.xlabel('Date')

            plt.ylabel('Count')

            plt.xticks(rotation=20)

            export_pdf.savefig()  # to save the plot

            export_pdf.close()  # close the created pdf



except ValueError:

    print('No failure processes between {} and {}'.format(last_month, first))

    sys.exit(100)



except Exception as e:

    print(e)