関連ワード:  python dataframe count occurrences in column    python pandas count occurrences in column    pandas dataframe count occurrences in column    pandas count occurrences in column    pandas count occurrences in column group by    pandas count occurrences in column with condition    python count value occurrences in dataframe column    python count number of occurrences in data frame column  
結果 : python dataframe count occurrences in column