code: def _checkNumerical(inputvalue, minvalue=None, maxvalue=None, description='inputvalue'):
      
      # Type checking
      if not isinstance(description, str):
          raise TypeError('The description should be a string. Given: {0!r}'.format(description))
  
      if not isinstance(inputvalue, (int, long, float)):
          raise TypeError('The {0} must be numerical. Given: {1!r}'.format(description, inputvalue))
  
      if not isinstance(minvalue, (int, float, long, type(None))):
          raise TypeError('The minvalue must be numeric or None. Given: {0!r}'.format(minvalue))
  
      if not isinstance(maxvalue, (int, float, long, type(None))):
          raise TypeError('The maxvalue must be numeric or None. Given: {0!r}'.format(maxvalue))
  
      # Consistency checking
      if (not minvalue is None) and (not maxvalue is None):
          if maxvalue < minvalue:
              raise ValueError('The maxvalue must not be smaller than minvalue. Given: {0} and {1}, respectively.'.format( \
                  maxvalue, minvalue))
  
      # Value checking
      if not minvalue is None:
          if inputvalue < minvalue:
              raise ValueError('The {0} is too small: {1}, but minimum value is {2}.'.format( \
                  description, inputvalue, minvalue))
  
      if not maxvalue is None:
          if inputvalue > maxvalue:
              raise ValueError('The {0} is too large: {1}, but maximum value is {2}.'.format( \
                  description, inputvalue, maxvalue))
docs: Check that the given numerical value is valid.
  
      Args:
          * inputvalue (numerical): The value to be checked.
          * minvalue (numerical): Minimum value  Use None to skip this part of the test.
          * maxvalue (numerical): Maximum value. Use None to skip this part of the test.
          * description (string): Used in error messages for the checked inputvalue
  
      Raises:
          TypeError, ValueError
  
      Note: Can not use the function :func:`_checkString`, as it uses this function internally.