제로베이스 데이터취업스쿨 DAY20 EDA 범죄1~2

피벗테이블

1) index

• pd.pivot_table(df, index=["Name"])
• pd.pivot_table(df, index=["Name","Rep","Manager"])

2) index, values

• pd.pivot_table(df, index=["Name"], values=["Price"])
  (평균이 디폴트)

3) index, values, aggfunc

• pd.pivot_table(df, index=["Name"], values=["Price"], aggfunc=np.sum)
• pd.pivot_table(df, index=["Name"], values=["Price"], aggfunc=[np.sum, len])
  (len : 개수)

4) index, values, aggfunc, columns
(columns : 분류 지정)

• pd.pivot_table(df, index=["Name", "Rep"], values=["Price"], columns=["Product"], aggfunc=[np.sum])

5) index, values, aggfunc, columns, fill_value

• pd.pivot_table(df, index=["Name", "Rep"], values=["Price"], columns=["Product"], aggfunc=[np.sum], fill_value=0)

6) pivot(인덱스, 열, value)

• flights = flights.pivot("month","year","passengers")

7) 다중컬럼
crime_station.columns = crime_station.columns.droplevel([0,1])
crime_station.columns.get_level_values(0)