\begin{Verbatim}[commandchars=\\\{\}]
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{k+kn}{from} \PYG{n+nn}{Bio} \PYG{k+kn}{import} \PYG{n}{SeqIO}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{record\PYGZus{}iterator} \PYG{o}{=} \PYG{n}{SeqIO}\PYG{o}{.}\PYG{n}{parse}\PYG{p}{(}\PYG{l+s+s2}{\PYGZdq{}ls\PYGZus{}orchid.fasta\PYGZdq{}}\PYG{p}{,} \PYG{l+s+s2}{\PYGZdq{}fasta\PYGZdq{}}\PYG{p}{)}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{first\PYGZus{}record} \PYG{o}{=} \PYG{n+nb}{next}\PYG{p}{(}\PYG{n}{record\PYGZus{}iterator}\PYG{p}{)}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{first\PYGZus{}record}\PYG{o}{.}\PYG{n}{id} \PYG{o}{=} \PYG{l+s+s2}{\PYGZdq{}new\PYGZus{}id\PYGZdq{}}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{n}{first\PYGZus{}record}\PYG{o}{.}\PYG{n}{description} \PYG{o}{=} \PYG{n}{first\PYGZus{}record}\PYG{o}{.}\PYG{n}{id} \PYG{o}{+} \PYG{l+s+s2}{\PYGZdq{} \PYGZdq{}} \PYG{o}{+} \PYG{l+s+s2}{\PYGZdq{}desired new description\PYGZdq{}}
\PYG{g+gp}{\PYGZgt{}\PYGZgt{}\PYGZgt{} }\PYG{k}{print}\PYG{p}{(}\PYG{n}{first\PYGZus{}record}\PYG{o}{.}\PYG{n}{format}\PYG{p}{(}\PYG{l+s+s2}{\PYGZdq{}fasta\PYGZdq{}}\PYG{p}{)[:}\PYG{l+m+mi}{200}\PYG{p}{])}
\PYG{g+go}{\PYGZgt{}new\PYGZus{}id desired new description}
\PYG{g+go}{CGTAACAAGGTTTCCGTAGGTGAACCTGCGGAAGGATCATTGATGAGACCGTGGAATAAA}
\PYG{g+go}{CGATCGAGTGAATCCGGAGGACCGGTGTACTCAGCTCACCGGGGGCATTGCTCCCGTGGT}
\PYG{g+go}{GACCCTGATTTGTTGTTGGGCCGCCTCGGGAGCGTCCATGGCGGGT}
\end{Verbatim}
