class_docstr: Calculate the population standard of deviation of a column.
  
  For the sample standard of deviation see :class:`.StDev`.
  
  :param column_name:
      The name of a column containing :class:`.Number` data.
class_docstr_tok: ["Calculate","the","population","standard","of","deviation","of","a","column",".","For","the","sample","standard","of","deviation","see",":","class",":","`",".StDev","`",".",":","param","column_name",":","The","name","of","a","column","containing",":","class",":","`",".Number","`","data","."]
code: def get_aggregate_data_type(self, table):
      return Number()
  
file_path: agate/agate/aggregations/stdev.py
imports: from agate.aggregations import Aggregation
  from agate.aggregations.has_nulls import HasNulls
  from agate.aggregations.variance import PopulationVariance, Variance
  from agate.data_types import Number
  from agate.exceptions import DataTypeError
  from agate.warns import warn_null_calculation
label_desc: Use image node_id 2 for calling the PopulationStDev obj's underlying member method code with example usage: obj.get_aggregate_data_type(table) and returns: Number