\end{verbatim}
\end{funcdesc}
+\begin{funcdesc}{b2a_hex}{data}
+Return the hexadecimal representation of the binary \var{data}. Every
+byte of \var{data} is converted into the corresponding 2-digit hex
+representation. The resulting string is therefore, twice as long as
+the length of \var{data}. This function is also available as
+\function{hexlify()}.
+\end{funcdesc}
+
+\begin{funcdesc}{a2b_hex}{hexstr}
+Return the binary data represented by the hexadecimal string
+\var{hexstr}. This function is the inverse of \function{b2a_hex()}.
+\var{hexstr} must contain an even number of hexadecimal digits (which
+can be upper or lower case), otherwise a \exception{TypeError} is
+raised. This function is also available as \function{unhexlify()}.
+
\begin{excdesc}{Error}
Exception raised on errors. These are usually programming errors.
\end{excdesc}