including Zeros counts categories with pandas value_counts()
I got the answer use of Series.reindex with a list of all categories and if not match replace to 0
  categories = ['a', 'b', 'c', 'd', 'e']
  pd.concat([df.col1.value_counts().reindex(categories[::-1], fill_value=0),        df.col1.value_counts(normalize=True).reindex(categories[::-1], fill_value=0).mul(100).round(1).astype(str) + '%'],axis=1, keys=('Counts','Percentage'))

This worked for me