@cache_readonly
    def groups(self):

        # this is mainly for compat
        # GH 3881
        result = {}
        for key, value in zip(self.binlabels, self.bins):
            if key is not tslib.NaT:
                result[key] = value
        return result
dict {group name -> group labels}
dataset/ETHPy150Open pydata/pandas/pandas/core/groupby.py/BinGrouper.groups