"Peter Hansen" <[EMAIL PROTECTED]> wrote: > Jp Calderone wrote: > > On Sat, 16 Jul 2005 19:01:50 -0400, Peter Hansen <[EMAIL PROTECTED]> wrote: > >> George Sakkis wrote: > >>>>>> identity = string.maketrans('','') > >> > >> Wow! That's handy, not to mention undocumented. (At least in the > >> string module docs.) Where did you learn that, George? > >> > > http://python.org/doc/lib/node109.html > > Perhaps I was unclear. I thought it would be obvious that I knew where > to find the docs for maketrans(), but that the particular behaviour > shown (i.e. arguments of '' having that effect) was undocumented in that > page. > > -Peter
Actually I first read about this in the Cookbook; there are two or three recipes related to string.translate. As for string.maketrans, it doesn't do anything special for empty string arguments: maketrans( from, to) Return a translation table suitable for passing to translate() or regex.compile(), that will map each character in from into the character at the same position in to; from and to must have the same length. So if from and to are empty, maketrans will map zero characters, hence the identity. It's not the only way to get the identity translation table by the way: >>> string.maketrans('', '') == string.maketrans('a', 'a') == >>> string.maketrans('hello', 'hello') True George -- http://mail.python.org/mailman/listinfo/python-list