Comparing Python to various other languages:
Full Treatments:
External Articles:
Several: Lutz Prechelt's article [http://www.ipd.uka.de/~prechelt/Biblio/ An Empirical Comparison of C, C++, Java, Perl, Python, Rexx, and Tcl for a Search/String-Processing Program] is a little old ((c) 2000), but it is REAL RESEARCH, comparing productivity and program performance for 80 different implementations of the same requirements, in 7 languages.
Several: Guido's essay [http://www.python.org/doc/essays/comparisons.html Comparing Python to Other Languages] is quite old (1997).
Several: GlyphLefkowitz wrote, and MikeConnell updated some very simple [http://www.flat222.org/mac/bench/ performance benchmarks]. Since 2002 this is no longer being updated.
Perl: In [http://www.linuxjournal.com/article.php?sid=3882 Why Python] Eric Raymond describes how he discovered Python, how it compares to Perl, and why he was impressed.
Perl: The humorous [http://www.python.org/doc/Humor.html#yoda Python vs. Perl according to Yoda].
Lisp: Peter Norvig wrote [http://www.norvig.com/python-lisp.html Python for Lisp Programmers] which includes a feature-by-feature comparison.
Lisp: There is a pretty terrible comparison of Python and Lisp (in the sense of being uninformed about Lisp) at http://www.strout.net/python/pythonvslisp.html. The only reason for mentioning it is to say, yes, it's old and inaccurate, and not to take it too seriously (you can seach comp.lang.lisp for more specific refutations if you really want).
Tcl: Frank Stajano's paper, [http://www.foretec.com/python/workshops/1998-11/proceedings/papers/stajano/stajano.html Implementing the SMS server, or why I switched from Tcl to Python], was presented at the [http://www.foretec.com/python/workshops/1998-11/ Seventh Internation Python Conference] (in 1998). (Also available in [http://www-lce.eng.cam.ac.uk/~fms27/papers/tr-1998-9.pdf PDF].)
... please add more!
See also WeakTyping.