\begin{Verbatim}[commandchars=\\\{\}]
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{k+kn}{from} \PYG{n+nn}{Bio.Seq} \PYG{k+kn}{import} \PYG{n}{Seq}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{k+kn}{from} \PYG{n+nn}{Bio.Alphabet} \PYG{k+kn}{import} \PYG{n}{IUPAC}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{dna\PYGZus{}seq} \PYG{o}{=} \PYG{n}{Seq}\PYG{p}{(}\PYG{l+s+s2}{\PYGZdq{}ACGT\PYGZdq{}}\PYG{p}{,} \PYG{n}{IUPAC}\PYG{o}{.}\PYG{n}{unambiguous\PYGZus{}dna}\PYG{p}{)}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{dna\PYGZus{}seq}
\PYG{g+go}{Seq(\PYGZsq{}ACGT\PYGZsq{}, IUPACUnambiguousDNA())}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{dna\PYGZus{}seq}\PYG{o}{.}\PYG{n}{lower}\PYG{p}{()}
\PYG{g+go}{Seq(\PYGZsq{}acgt\PYGZsq{}, DNAAlphabet())}
\end{Verbatim}
