分散したい（`pandas.DataFrame.var`）

data["var"] = data["カラム名"].var()

分散

\[V = s^{2} = \frac{1}{n} \sum_{i=1}^{n} (x_{i} - m)^{2} \]

\[V = s^{2} = \frac{1}{n-1} \sum_{i=1}^{n} (x_{i} - m)^{2} \]