Why is Python popular, while Lisp and Scheme aren't?

[Andreas Leitgeb]

Jacek Generowicz <jacek.generowicz at cern.ch> wrote:
> (defun Hpp (x s z)
>   #i(sqrt(Vpp(x s z)-gamma)/(x^2+s^4) -
>      exp(sin(Tpp(x s))/(2*b1(x s)))))

I once came in touch with lisp/scheme, when I tried to modify
one of the card-games in AisleRiot.  The games themselves are 
written in scheme, and make heavy use of  "and" and "or" to
achieve the effect of lots of nested if-else-constructs.

Maybe it's not the lisp-syntax itself, that is so ugly, but
rather the (seemingly typical) coding-style.

I quote one function from AisleRiot  (game Kansas):
" (define (button-pressed slot-id card-list)
"  (and (not (= (length card-list) 0))
"       (is-visible? (car card-list))
"       (or (= slot-id 1)
"           (> slot-id 5))))
If you still find this readable, then look at "button-released"
 immediately following in kansas.scm  (same structure but two 
 pages long and deeper nested)

PS: Not to mention that the error messages for runtime errors
  are far from being helpful - compared to tcl's exception 
  tracebacks.