\ExplSyntaxOn
\newcommand{\pyval}[1]{%
	\str_case:nn{#1}{%
		{ 0 }{ m = \SI{-7.2588+-0.0000}{  }}
		{ 1 }{ p = \SI{2436.5476+-0.0000}{  }}
		{ 2 }{ a = \SI{-2666.0034+-0.0000}{  }}
		{ 3 }{ c = \SI{0.9318+-0.0000}{  }}
	}
}
\ExplSyntaxOff