Create a pandas dataframe of counts

Another way to do this, using value_counts:

In [10]: df = pd.DataFrame({'Color': ['Red', 'Red', 'Blue'], 'State': ['MA', 'PA', 'PA']})

In [11]: df.Color.value_counts().reset_index().rename(
           columns={'index': 'Color', 0: 'count'})
Out[11]:
  Color  count
0   Red      2
1  Blue      1

Essentially equivalent to setting the column names, but using the rename method instead:

df.groupby('Color').count().reset_index().rename(columns={'State': 'Count'})