Pandas DataFrame 之 groupby()

groupby()

groupby() 方法定义：

DataFrame.groupby(
    by=None, 
    axis=0, 
    level=None, 
    as_index=True, 
    sort=True, 
    group_keys=True, 
    squeeze=NoDefault.no_default,
    observed=False, 
    dropna=True
    ) -> DataFrameGroupBy