\begin{Verbatim}[commandchars=\\\{\}]
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{k+kn}{from} \PYG{n+nn}{Bio.Align.substitution\PYGZus{}matrices} \PYG{k+kn}{import} \PYG{n}{Array}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{d} \PYG{o}{=} \PYG{n}{Array}\PYG{p}{(}\PYG{l+s+s2}{\PYGZdq{}ACGT\PYGZdq{}}\PYG{p}{)}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{r} \PYG{o}{=} \PYG{n}{Array}\PYG{p}{(}\PYG{l+s+s2}{\PYGZdq{}ACGU\PYGZdq{}}\PYG{p}{)}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{d} \PYG{o}{+} \PYG{n}{r}
\PYG{g+gt}{Traceback (most recent call last):}
    \PYG{o}{...}
\PYG{g+gr}{ValueError}: \PYG{n}{alphabets are inconsistent}
\end{Verbatim}
