Known bugs

Almost any Python code should execute correctly when run under Psyco, including code that uses arbitrary C extension modules. Some features of Python which are marked as ``not supported'' by Psyco will not cause Psyco to fail to produce the correct result; instead, it will revert to the regular Python interpreter and the code will run non-accelerated.

All exceptions to this rule are bugs, but there are a couple of them because they would be either very hard to fix or fixing them would severely hurt performance. They correspond to uncommon situations. The current list is in appendix .

There are also performance bugs: situations in which Psyco slows down the code instead of accelerating it. It is difficult to make a complete list of the possible reasons, but here are a few common ones:

• The built-in map and filter functions must be avoided and replaced by list comprehension. For example, map(lambda x: x*x, lst) should be replaced by the more readable but more recent syntax [x*x for x in lst].
• The compilation of regular expressions doesn't seem to benefit from Psyco. (The execution of regular expressions is unaffected, since it is C code.) Don't enable Psyco on this module; if necessary, disable it explicitely, e.g. by calling psyco.cannotcompile(re.compile).