@Substitution(name='<STR_LIT>')<EOL><INDENT>@Appender(_doc_template)<EOL>@Appender(_bias_template)<EOL>def std(self, bias=False, *args, **kwargs):<DEDENT>
nv.validate_window_func('<STR_LIT>', args, kwargs)<EOL>return _zsqrt(self.var(bias=bias, **kwargs))<EOL>
Exponential weighted moving stddev.