def _unary_compiler(tmpl):
    return lambda self, x: tmpl % self.compile(x)
Standard deviation. Square root of the variance.
dataset/ETHPy150Open mbr/Babel-CLDR/babel/plural.py/_unary_compiler--crossover with--dataset/ETHPy150Open mahmoud/boltons/boltons/statsutils.py/Stats._calc_std_dev