code: def validate(self, instance, value):
          
          try:
              floatval = float(value)
              if not self.cast and abs(value - floatval) > TOL:
                  self.error(
                      instance=instance,
                      value=value,
                      extra='Not within tolerance range of {}.'.format(TOL),
                  )
          except (TypeError, ValueError):
              self.error(instance, value, extra='Cannot cast to float.')
          _in_bounds(self, instance, floatval)
          return floatval
docs: Checks that value is a float and in min/max bounds
  
          Non-float numbers are coerced to floats