Loop performance disappearance
tim_one at email.msn.com
Thu Mar 16 02:19:22 CET 2000
> I always assumed (perhaps being too much of a newbie) that
> for i in range(n):
> would automatically be recognized by the compiler and turned into a simple
> loop control using i alone (like turning it into an xrange, I guess).
CPython is currently about as WYSIWYG as languages come.
Total number of lines of Python compiler code devoted to optimization: a
couple dozen, all related to speeding local vrbl access.
Total number of hours Python users have spent tracking down Python compiler
optimization bugs: 0.
Total number of hours Python users have spent tracking down optimization
bugs in the C compilers they use to compile Python: impossible to say, but
thousands is a conservative lower bound.
In time, you'll learn to write Python that's pretty quick. That the
language does exactly what you tell it to do is a great aid in this (e.g.,
"range" always returns a list, "xrange" never does -- does anyone really
need more info than that to know what to write next <wink>?).
y'rs - tim, who used to make his living writing optimizing compilers,
and finds Python a great relief <0.5 wink>.
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