code: def numeric_columns(self, include_bool=True):
          
          columns = []
          for col, dtype in zip(self.columns, self.dtypes):
              if is_numeric_dtype(dtype) and (
                  include_bool or (not include_bool and dtype != np.bool_)
              ):
                  columns.append(col)
          return columns
docs: Returns the numeric columns of the Manager.
  
          Returns:
              List of index names.