15 November 2010

Nuitka Release 0.3.3

This is to inform you about the new stable release of Nuitka. It is the extremely compatible Python compiler, “download now”.

This release of Nuitka continues the focus on performance. It also cleans up a few open topics. One is “doctests”, these are now extracted from the CPython 2.6 test suite more completely. The other is that the CPython 2.7 test suite is now passed completely. There is some more work ahead though, to extract all of the “doctests” and to do that for both versions of the tests.

This means an even higher level of compatibility has been achieved, then there is performance improvements, and ever cleaner structure.

Bug Fixes


  • Generator functions tracked references to the common and the instance context independently, now the common context is not released before the instance contexts are.

  • Generator functions didn’t check the arguments to throw() the way they are in CPython, now they do.

  • Generator functions didn’t trace exceptions to “stderr” if they occurred while closing unfinished ones in “del”.

  • Generator functions used the slightly different wordings for some error messages.

Function Calls

  • Extended call syntax with ** allows that to use a mapping, and it is now checked if it really is a mapping and if the contents has string keys.

  • Similarly, extended call syntax with * allows a sequence, it is now checked if it really is a sequence.

  • Error message for duplicate keyword arguments or too little arguments now describe the duplicate parameter and the callable the same way CPython does.

  • Now checks to the keyword argument list first before considering the parameter counts. This is slower in the error case, but more compatible with CPython.


  • The “locals()” built-in when used in the class scope (not in a method) now is correctly writable and writes to it change the resulting class.

  • Name mangling for private identifiers was not always done entirely correct.


  • Exceptions didn’t always have the correct stack reported.

  • The pickling of some tuples showed that “cPickle” can have non-reproducible results, using “pickle” to stream constants now


  • Access to instance attributes has become faster by writing specific code for the case. This is done in JIT way, attempting at run time to optimize attribute access for instances.

  • Assignments now often consider what’s cheaper for the other side, instead of taking a reference to a global variable, just to have to release it.

  • The function call code built argument tuples and dictionaries as constants, now that is true for every tuple usage.


  • The static helper classes, and the prelude code needed have been moved to separate C++ files and are now accessed “#include”. This makes the code inside C++ files as opposed to a Python string and therefore easier to read and or change.

New Features

  • The generator functions and generator expressions have the attribute “gi_running” now. These indicate if they are currently running.

New Tests

  • The script to extract the “doctests” from the CPython test suite has been rewritten entirely and works with more doctests now. Running these tests created increased the test coverage a lot.

  • The Python 2.7 test suite has been added.


  • One can now run multiple “compare_with_cpython” instances in parallel, which enables background test runs.

  • There is now a new environment variable “NUITKA_INCLUDE” which needs to point to the directory Nuitka’s C++ includes live in. Of course the “create-environment.sh” script generates that for you easily.


python 2.6:

Pystone(1.1) time for 50000 passes = 0.65
This machine benchmarks at 76923.1 pystones/second

Nuitka 0.3.3:

Pystone(1.1) time for 50000 passes = 0.36
This machine benchmarks at 138889 pystones/second

This is 80% for 0.3.3, up from 66% before.