text: # Copyright 1999-2021 Alibaba Group Holding Ltd.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from ...tensor.arithmetic import sqrt
  from .var import var_dataframe, var_series
  
  
  def std_dataframe(
      df,
      axis=None,
      skipna=None,
      level=None,
      ddof=1,
      numeric_only=None,
      combine_size=None,
      method=None,
  ):
      ret = sqrt(
          var_dataframe(
              df,
              axis=axis,
              skipna=skipna,
              level=level,
              ddof=ddof,
              numeric_only=numeric_only,
              combine_size=combine_size,
              method=method,
          )
      )
      return ret
  
  
  def std_series(
      series, axis=None, skipna=None, level=None, ddof=1, combine_size=None, method=None
  ):
      ret = sqrt(
          var_series(
              series,
              axis=axis,
              skipna=skipna,
              level=level,
              ddof=ddof,
              combine_size=combine_size,
              method=method,
          )
      )
      return ret
  