df.loc 和值计数

Question

So I am trying to get the first letter of a column and then get the value counts for that letter

df5 = pd.DataFrame(df['EmployeeLastName'].astype(str).str[0].value_counts()) 

and then select only the values that are more than 50

df5.loc[df5['EmployeeLastName'] > 50]

Is there a way I can accomplish this without creating a new data frame?

I tried this put it is resulting in an error.

df.loc[ df['EmployeeLastName'].astype(str).str[0].value_counts() > 50 ]

Thanks

Answer 1

Use groupby and transform

df.loc[(df.groupby(df['EmployeeLastName'].str[0])
          .transform('count') > 50).squeeze()]