Mailman 3 November 2003 - Python-Dev

possible backward incompatibility in test.regrtest
by Tamito KAJIYAMA 01 Dec '03

01 Dec '03

Hi developers, It seems that the test.regrtest module has a possible backward incompatibility with regard to pre-Python 2.3 releases. I have a test suit implemented using the test.regrtest module. In this test suit, my own tests are invoked by a script like this: import os from test import regrtest regrtest.STDTESTS = [] regrtest.main(testdir=os.getcwd()) This script runs fine with 2.2 but does not with 2.3, since regrtest.py in Python 2.3 has the following lines in runtest() (introduced in Revision 1.87.2.1. See [1]): if test.startswith('test.'): abstest = test else: # Always import it from the test package abstest = 'test.' + test the_package = __import__(abstest, globals(), locals(), []) That is, tests must be in a package named "test". However, this package name is already used by the standard library, and AFAIK multiple packages with the same package name cannot exist. In other words, any additional tests (i.e. my own tests) have to be put into the test package in the standard library. Otherwise, the additional tests won't be found. IMHO, this change in 2.3 is not reasonable. Unless I miss something trivial (I hope so), I'd have to give up using the test.regrtest module. I appreciate any comment. Thanks, -- KAJIYAMA, Tamito <kajiyama(a)grad.sccs.chukyo-u.ac.jp> [1] http://cvs.sourceforge.net/viewcvs.py/python/python/dist/src/Lib/test/regrt…

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Use of Python Versions
by Neal Norwitz 30 Nov '03

30 Nov '03

I conducted an experiment to try to find out what versions of Python people use. In the last release of pychecker, I asked people to take a survey (http://metaslash.com/pyversion.html). While not scientific, it provides some info. There were 186 responses, with 2 apparent duplicates. Nobody used only one version of Python with that version being 2.1 or below. 110 people only use a single version of python with 10 using 2.2 only, 108 using 2.3 only, and 2 using 2.4 only. Here are the total number of responses by version: 1.5 5, all 5 also use 2.3 2.0 3 2.1 13 2.2 72 2.3 172 2.4 23 The raw responses are here: http://metaslash.com/pyver.txt Neal

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Weekly Python Bug/Patch Summary
by Skip Montanaro 30 Nov '03

30 Nov '03

Bug/Patch Summary ----------------- 590 open / 4387 total bugs (+63) 207 open / 2476 total patches (+28) New Bugs -------- XMLGenerator.startElementNS dies on EMPTY_NAMESPACE attribut (2003-11-23) http://python.org/sf/847665 Keyword similar to "global" for nested scopes wanted (2003-11-23) http://python.org/sf/847778 64 bit solaris versus /usr/local/lib (2003-11-23) http://python.org/sf/847812 4.2.6 (re) Examples: float regexp exponential on failure (2003-11-24) http://python.org/sf/848556 couple of new list.sort bugs (2003-11-25) http://python.org/sf/848856 Windows installer halts (2003-11-25) http://python.org/sf/848871 pydoc crash on MacOS X (2003-11-25) http://python.org/sf/848907 gzip.GzipFile is slow (2003-11-25) http://python.org/sf/849046 Request: getpos() for sgmllib (2003-11-25) http://python.org/sf/849097 ZipInfo shows incorrect file size for large files (2003-11-25) http://python.org/sf/849218 reading shelves is really slow (2003-11-26) http://python.org/sf/849662 unclear documentation/missing command? (2003-11-27) http://python.org/sf/850238 Typo in Popen3 description (2003-11-28) http://python.org/sf/850818 Doc/README has broken link (2003-11-28) http://python.org/sf/850823 optparse: OptionParser.__init__'s "prog" argument ignored (2003-11-28) http://python.org/sf/850964 test_poll fails in 2.3.2 on MacOSX(Panther) (2003-11-28) http://python.org/sf/850981 mbcs encoding ignores errors (2003-11-28) http://python.org/sf/850997 building on Fedora Core 1 (2003-11-28) http://python.org/sf/851020 winreg can segfault (2003-11-28) http://python.org/sf/851056 shutil.copy destroys hard links (2003-11-29) http://python.org/sf/851123 Item out of order on builtin function page (2003-11-29) http://python.org/sf/851152 Bug tracker page asks for login even when logged in (2003-11-29) http://python.org/sf/851156 New-style classes with __eq__ but not __hash__ are hashable (2003-11-29) http://python.org/sf/851449 New Patches ----------- Port tests to unittest (Part 2) (2003-05-13) http://python.org/sf/736962 SimpleHTTPServer reports wrong content-length for text files (2003-11-10) http://python.org/sf/839496 Extend struct.unpack to produce nested tuples (2003-11-23) http://python.org/sf/847857 Cookie.py: One step closer to RFC 2109 (2003-11-23) http://python.org/sf/848017 Flakey urllib2.parse_http_list (2003-11-25) http://python.org/sf/848870 Small error in test_format (2003-11-25) http://python.org/sf/849252 832799 proposed changes (2003-11-25) http://python.org/sf/849262 improve embeddability of python (2003-11-25) http://python.org/sf/849278 urllib reporthook could be more informative (2003-11-25) http://python.org/sf/849407 Enhance frame handing in warnings.warn() (2003-11-27) http://python.org/sf/850482 Semaphore.acquire() timeout parameter (2003-11-28) http://python.org/sf/850728 call com_set_lineno more often (2003-11-28) http://python.org/sf/850789 Modify Setup.py to Detect Tcl/Tk on BSD (2003-11-28) http://python.org/sf/850977 Argument passing from /usr/bin/idle2.3 to idle.py (2003-11-29) http://python.org/sf/851459 Closed Bugs ----------- Dialogs too tight on OSX (2002-10-29) http://python.org/sf/630818 MacPython for Panther additions includes IDLE (2003-11-08) http://python.org/sf/838616 SimpleHTTPServer reports wrong content-length for text files (2003-11-10) http://python.org/sf/839496 PackMan database for panther misses devtools dep (2003-11-14) http://python.org/sf/842116 PackageManager: deselect show hidden: indexerror (2003-11-18) http://python.org/sf/844676 error in python's grammar (2003-11-21) http://python.org/sf/846521 "and" operator tests the first argument twice (2003-11-21) http://python.org/sf/846564 Closed Patches --------------

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"groupby" iterator
by Guido van Rossum 30 Nov '03

30 Nov '03

In the shower (really!) I was thinking about the old problem of going through a list of items that are supposed to be grouped by some key, and doing something extra at the end of each group. I usually end up doing something ugly like this: oldkey = None for item in sequence: newkey = item.key # this could be any function of item if newkey != oldkey and oldkey is not None: ...do group processing... oldkey = newkey ...do item processing... ...do group processing... # for final group This is ugly because the group processing code has to be written twice (or turned into a mini-subroutine); it also doesn't handle empty sequences correctly. Solutions based on using an explicit index and peeking ahead are similarly cumbersome and hard to get right for all end cases. So I realized this is easy to do with a generator, assuming we can handle keeping a list of all items in a group. Here's the generator: def groupby(key, iterable): it = iter(iterable) value = it.next() # If there are no items, this takes an early exit oldkey = key(value) group = [value] for value in it: newkey = key(value) if newkey != oldkey: yield group group = [] oldkey = newkey group.append(value) yield group Here's the usage ("item.key" is just an example): for group in groupby(lambda item: item.key, sequence): for item in group: ...item processing... ...group processing... The only caveat is that if a group is very large, this accumulates all its items in a large list. I expect the generator can be reworked to return an iterator instead, but getting the details worked out seems too much work for a summy Thanskgiving morning. :-) Example: # Print lines of /etc/passwd, sorted, grouped by first letter lines = open("/etc/passwd").readlines() lines.sort() for group in groupby(lambda s: s[0], lines): print "-"*10 for line in group: print line, print "-"*10 Maybe Raymond can add this to the itertools module? Or is there a more elegant approach than my original code that I've missed all these years? --Guido van Rossum (home page: http://www.python.org/~guido/)

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Telnet server
by sa 29 Nov '03

29 Nov '03

Hi all, I want to develop a thin telnet server using the curses library .First of all is this possible ? The box on which I want to develop this, does not provide a shell as it runs customized embedded linux so i want to write a telnet server on the box which presents the telnet client, a curses kinda intrface after he gets past the login prompt authentication. I can execute my python scripts on this box without any problems . Any pointers ? Thanks,

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Banishing apply(), buffer(), coerce(), and intern()
by Raymond Hettinger 29 Nov '03

29 Nov '03

After re-reading previous posts on the subject, I had an idea. Let's isolate these functions in the documentation into a separate section following the rest of the builtins. The cost of having these builtins is not that they take up a few entries in the directory listing. Also, it's no real burden to leave them in the code base. The real cost is that when learning the language, after reading the tutorial, the next step is to make sure you know what all the builtins do before moving on to study the library offerings. The problem with buffer() and intern() is not that they are totally useless. The problem is that it that it is darned difficult an everyday user to invent productive use cases. Here on python-dev, one defender arose for each and said that they once had a use for them. So, let's leave the functionality intact and just move it off the list of things you need to know. In both cases, it would have saved me some hours spent trying to figure out what they were good for - I wish someone had just said, "you can ignore these two". These functions are just distractors in a person's mental concept space. There's really nothing wrong with have apply() and coerce() being supported for old code. The problem with them is why bother even knowing that they exist - they just don't figure into modern python code. Any time spent learning them now is time that could have been spent learning about the copy or pickle modules or some such. Moving these functions to a separate section sends a clear message to trainers and book writers that it is okay to skip these topics. Getting them out of the critical path for learning python will make the language even easier to master. Some are highly resistant to deprecation because it makes their lives more difficult. However, I think even they would like a list of "things you just don't need to know anymore". In other words, you don't have to wait for Py3.0 for a clean house, just push all the clutter in a corner and walk around it. 'nuff said, Raymond Hettinger

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Thesis ideas list
by Brett C. 29 Nov '03

29 Nov '03

As requested, here is a annotated list of the ideas that I received for my masters thesis. I tried to do a decent job of referencing where info is and summarizing the emails I received. I also did **very** rough commenting on each of them in trying to understand them and to see if I thought they would make a good thesis for me. If you have something to contribute to the list, please do so. Don't bother with spelling and grammatical fixes, though, since this is just for my personal use and for anyone interested in the ideas; it will not see the light of day on python.org or anything unless someone else decides to put the effort into that. I am planning to go in and talk with my thesis advisor after Thanksgiving break (next week) to try to narrow down the list so I can have a thesis topic chosen by Jan 1. ---------------------------------- ===== Misc. ===== Annotations ----------- from Martin: http://mail.python.org/pipermail/python-dev/2003-October/039768.html and http://mail.python.org/pipermail/python-dev/2003-October/039809.html Similar to attributes as done in .NET . Michael's ``func()[]`` syntax might pull off what Martin wants. For an overview of attributes in C#, see http://www.ondotnet.com/pub/a/dotnet/excerpt/prog_csharp_ch18/index.html?pa… . They appear to be a way to connect data with code. Using reflection you can find out what attributes are attached to an object. You can control what types of objects an attribute can be bound to along with specifying arguments. It seems like the compiler has some built-in attributes that it uses to process the code when available. Since it not only just attaches info to an object, but it is used by the language to modify the code. It seems like the func()[] syntax along with Python's dynamic attribute creation covers this, just without the built-in syntax. Could be interesting to come up with a variance on descriptors for assigning to something like __metadict__. If it is a data descriptor it is just attached as info to the ojbect. If it a non-data descriptor, though, it gets the code object passed to it. The only perk of this is a way to have info attached in a more abstracted way than just sticking the info into __dict__ and making sure you don't overwrite the value (in other words __metadict__ would not come into play for name resolution). Basically just standard place to store metadata. Martin's suggestion was having an attribute that would automatically create an XML-RPC interface for a code object. That might be doable as a metaclass, but that could get complicated and messy. If you could do something like:: def meth() [xml-rpcbuilder]: pass and have 'meth' automatically get an ``annotation(meth, 'xml-rpc')`` ability that returns a wrapper implementing an XML-RPC interface that might be cool. You could do this now with a function that takes something, creates a wrapper, and then stores it on the object so that it does not have to be recreated every time. But that becomes an issue of overwriting values in the object. Having a place for metadata would lesson that problem somewhat. All in all it *might* be a good thing, but with Python dynamicism I don't see a use-case for it at this moment. Work on PyPy ------------ from `Holger <http://mail.python.org/pipermail/python-dev/2003-October/039772.html>`__ Vague statement that one could work on PyPy. OSCON 2003 paper at http://codespeak.net/pypy/index.cgi?doc/oscon2003-paper.html . PyPy's EU funding proposal has interesting parts at http://codespeak.net/pypy/index.cgi?doc/funding/B1.0 and http://codespeak.net/pypy/index.cgi?doc/funding/B6.0 . Multiple dispatch ----------------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ Look at Dylan_ and Goo_ for inspiration. An explanation of how Dylan does multiple dispatch can be seen at http://www.gwydiondylan.org/gdref/tutorial/multiple-dispatch.html . Multiple dispatch is basically a mechanism of registering a group of methods under one generic method that then calls the registered methods based on whether the parameter lists can match the arguments being passed. If there is more than one match then they are ordered in terms of how "specific" they are; if a parameter requires a subclass or the actual class it is less specific. Methods can then call a special method that will call the next method in the calculated order. The issue with this in terms of Python is how to handle comparing the arguments given to a method when a parameter list is just so damn vague. If you have the parameter lists, ``def A(arg1, arg2, *args)`` and ``def B(*args)``, which one is more specific? The other issue is that since Python has not parameter type-checking beyond argument counts you can't base whether a method is more specific or not on the type or arguments. In order for this to be built into the language one would have to add type-checking first. Otherwise one would need to have all of this be external to the language. It should be doable in terms of Python code now. Building it into the language might be nice, but without type checking I don't know how useful it would be. .. _Dylan: http://www.gwydiondylan.org/drm/drm_1.htm .. _Goo: http://www.ai.mit.edu/~jrb/goo/manual/goomanual.html Static analysis of Python C code -------------------------------- from Neal (private email) Look at the work done by `Dawson Engler`_. Could check for missing DECREF/INCREFs, null pointer dereferences, threading issues, etc. Appears the research was developing a system to check that basic rules were met for code (returned values were checked, disabled interrupts get re-enabled, etc.). .. _Dawson Engler: http://www.stanford.edu/~engler/ ====== Memory ====== Mark-and-sweep GC ----------------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ Only really worth it in terms of code complexity (does C code become easier? How hard to move existing extension modules over?) and to measure performance difference. Chicken GC ---------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ with more ideas from `Samuele <http://mail.python.org/pipermail/python-dev/2003-October/039818.html>`__ and `Phillip Eby <http://mail.python.org/pipermail/python-dev/2003-October/039832.html>`__ Chicken_ has its GC covered in a paper entitled "`Cheney on the M.T.A.`_". Seems to be the one Neil likes the most. Interestingly, Chicken (which is a Scheme-to-C compiler) does all memory allocation on the stack. .. _Chicken: http://www.call-with-current-continuation.org/chicken.html .. _Cheney on the M.T.A.: http://citeseer.nj.nec.com/baker94cons.html Boehm-Demers-Weiser collector ----------------------------- from `Jeremy <http://www.python.org/~jeremy/weblog/031029c.html>`__ The collector can be found at http://www.hpl.hp.com/personal/Hans_Boehm/gc/index.html . It is a generic mark-and-sweep collector that has been designed to be portable and easy to use. Analyze memory usage -------------------- from `Jeremy <http://www.python.org/~jeremy/weblog/031029c.html>`__ Apparently `some guys`_ claim that a high-performance, general memory allocator works better than a bunch of custom allocators (Python has a bunch of the latter). .. _some guys: http://citeseer.nj.nec.com/berger01reconsidering.html ========= Threading ========= Provide free threading efficiently ---------------------------------- from `Martin <http://mail.python.org/pipermail/python-dev/2003-October/039768.html>`__ `In the free threading model, a client app may call any object method ... from any thread at any time. The object must serialize access to all of its methods to whatever extent it requires to keep incoming calls from conflicting, providing the maximum performance and flexibility. <http://www.microsoft.com/msj/0897/free.aspx>`__. In other words you shouldn't have to do any locking to do a method call. MP threading ------------ from `Dennis Allison <http://mail.python.org/pipermail/python-dev/2003-October/039779.html>`__ Try to eliminate the serialization of Python code execution because of the GIL. Look at research by `Maurice Herlihy`_ and `Kourosh Gharachorloo`_. .. _Maurice Herlihy: http://www.cs.brown.edu/people/mph/home.html .. _Kourosh Gharachorloo: http://research.compaq.com/wrl/people/kourosh/bio.html ========= Compiling ========= Python to C ----------- from `Fernando Perez <http://mail.python.org/pipermail/python-dev/2003-October/039780.html>`__ `Pat Miller`_ presented a paper on this for scientific work at SciPy 2003. Can look to Squeak_ for inspiration. .. _Pat Miller: http://www.llnl.gov/CASC/people/pmiller/ .. _Squeak: http://www.squeak.org/ Finish AST branch ----------------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ No research left, but could lead to macros_. Macros ------ from `Jeremy <http://www.python.org/~jeremy/weblog/031029c.html>`__ Once access to an AST is available, macros are doable. Lisp's macros work so well because of quasiquotation_. In order for this to work in Python, though, you need some other way to handle it; either through the AST like in Maya_ or the CST as in JSE_. Something else to look at is Polyglot_ (what Jeremy wishes the compiler package had become). .. _quasiquotation: http://citeseer.nj.nec.com/bawden99quasiquotation.html .. _Maya: http://citeseer.nj.nec.com/baker02maya.html .. _JSE: http://citeseer.nj.nec.com/context/1821961/0 .. _Polyglot: http://www.cs.cornell.edu/Projects/polyglot/ Refactoring code editor for AST ------------------------------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ Integrating XML and SQL into the language ----------------------------------------- from `Jeremy <http://www.python.org/~jeremy/weblog/031029c.html>`__ Seems to be to make XML and SQL first-class citizens in Python. Based on the work of `Erik Meijer`_. Paper at http://www.research.microsoft.com/~emeijer/Papers/XML2003/xml2003.html with his main research page at http://research.microsoft.com/~emeijer/ . .. _Erik Meijer: http://blogs.gotdotnet.com/emeijer/ Optional type checking ---------------------- from me, but with support from Guido (private email) Guido thinks it is "one tough problem". He suggested looking at the `types-sig archive`_ for ideas. Guido would love to have someone sanctioned to tackle this problem. Might be much easier to do if limited to only parameter lists. Doing that minimal amount would allow for a better multiple dispatch implementation. It would also allow for a rudimentary form of polymorphism based on parameter signatures. .. _types-sig archive: http://www.python.org/pipermail/types-sig/ Type inferencing ---------------- from `Martin <http://mail.python.org/pipermail/python-dev/2003-October/039768.html>`__ Either run-time or compile-time. "Overlap with the specializing compilers". Register-based VM ----------------- from Neal (private email) Should get a nice performance improvement. Look at Skip and Neil's rattler VM. Would be a step towards hooking Python into GCC for assembly code generation. Lower-level bytecode -------------------- from Neal (private email) Supposedly Java's bytecode is fairly low-level. Would make the transition to a register-based VM easier. Also would make compiling to machine code or JIT compilation simpler. An IBM developerWorks article on Java bytecode is available at http://www-106.ibm.com/developerworks/ibm/library/it-haggar_bytecode/ . Could look at assembly languages (RISC and CISC) and other VMs for ideas on bytecodes. ========= Execution ========= Portable floating point ----------------------- from Martin: http://mail.python.org/pipermail/python-dev/2003-October/039768.html and http://mail.python.org/pipermail/python-dev/2003-October/039809.html Come up with code on a per-platform basis to make up for problems on that platform's FPU implementation. Compare to how Python just provides the CPU's implementation while Java guarantees a specific semantic behavior by providing the needed code to make it the same on all platforms. Martin suggested looking at Java's strictfp mode (which was added after Java 1.0). See http://developer.java.sun.com/developer/JDCTechTips/2001/tt0410.html#using on its usage. Save interpreter state to disk ------------------------------ from `Martin <http://mail.python.org/pipermail/python-dev/2003-October/039768.html>`__ Similar to Smalltalk's images. Would be nice since would provide a fail-safe mechanism for long-running processes. Could also help with debugging by being able to pass around state of a program just before an error occurs. Deterministic Finalization -------------------------- from Martin: http://mail.python.org/pipermail/python-dev/2003-October/039768.html and http://mail.python.org/pipermail/python-dev/2003-October/039809.html Having objects implicitly destroyed at certain points. Example is threaded code (in Python):: def bump_counter(self): self.mutex.acquire() try: self.counter = self.counter+1 more_actions() finally: self.mutex.release() In C++, you do:: void bump_counter(){ MutexAcquistion acquire(this); this->counter+=1; more_actions(); which is nice since you don't have to explicitly release the lock. Optimize global namespace access -------------------------------- from `Neil <http://mail.python.org/pipermail/python-dev/2003-October/039778.html>`__ and `Jeremy <http://www.python.org/~jeremy/weblog/031029c.html>`__ Look at `PEP 267`_ and Jeremy's `Faster Namespace`_ slides from 10th Python conference. Neil pointed out that "If we can disallow inter-module shadowing of names the job becomes easier" (e.g., making ``import Foo; Foo.len = 42`` illegal). .. _PEP 267: http://www.python.org/peps/pep-0267.html .. _Faster Namespace: http://www.python.org/~jeremy/talks/spam10/PEP-267-1.html Restricted execution -------------------- from Andrew Bennett (private email) See the python-dev archives and Summaries for more painful details. Tail Recursion -------------- from Me (my brain) Have proper tail recursion in Python. Would require identifying where a direct function call is returned (could keep it simple and just do it where CALL_FUNCTION and RETURN bytecodes are in a row). Also have to deal with exception catching since that requires the frame to stay alive to handle the exception. But getting it to work well could help with memory and performance. Don't know if it has been done for a language that had exception handling.

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test_mimetools failure when hostname unknown.
by Anthony Baxter 29 Nov '03

29 Nov '03

If you have a machine who's local hostname is just something you've set, and there's no matching entry in /etc/hosts, test_mimetools fails with test test_mimetools failed -- Traceback (most recent call last): File "/home/anthony/src/py/23maint/Lib/test/test_mimetools.py", line 30, in test_boundary nb = mimetools.choose_boundary() File "/home/anthony/src/py/23maint/Lib/mimetools.py", line 130, in choose_boundary hostid = socket.gethostbyname(socket.gethostname()) gaierror: (-2, 'Name or service not known') This seems, to me, to be a bit bogus - should we just, in this case, have some sensible default (maybe just use the hostname, or 127.0.0.1) And yes, I know this is not strictly a python bug, but it just popped up while I was building a new system up. Anthony

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less quick patch for better debugging.
by Hunter Peress 28 Nov '03

28 Nov '03

Ah. Theres clearly interest in the idea. I guess its as simple as adding a field to Py_Object that would record the last namespace name used for a given object (remember any object could have many names...) (not sure about Threads btw here). This would allow for all error lookup-type error messages to be much cleaner. The impetus for the above idea being an index error on the following line: a[1] + b[2] + c[3]...currently gives an error message that doesnt say which variable the list index error occurs in or at which index it occurs at (helpful if they were all the same object on the same line). Same issues go for dicts and even any object attributes as well. PS. maybe in the interest of runtime speed, the assigning to this new field could only occur when there actually is an error.

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Patch to distutils.msvccompiler, 2.3 branch
by Thomas Heller 28 Nov '03

28 Nov '03

Several people on this list (IIRC Jim, Guido, Jeremy) have been bitten by the problem that distutils couldn't build extensions with MSVC6, complaining that the compiler isn't installed although in fact it was installed. The problem always seemed to be that MSVC6 only writes the complete registry entries which distutils requires after the GUI has been run at least one time. I have uploaded a patch to the latest bug report from Jim, http://www.python.org/sf/848614, which tries to detect these incomplete registry entries. It works for me (having removed and installed MSVC several times, with and without running the gui). It would be great if someone else would try it out and report if it works correctly - IMO it should be commited to the 2.3 maintanance branch before 2.3.3 goes out. (Suggestions for better wording would be accepted ;-) The effect of this patch would be the folling outputs from a 'setup.py build_ext' command, depending on the compiler installation state: Not installed: error: Python was built with version 6 of Visual Studio, and extensions need to be built with the same version of the compiler, but it isn't installed. Installed, but the GUI has never been run: warning: It seems you have Visual Studio 6 installed, but the expected registry settings are not present. You must at least run the Visual Studio GUI once so that these entries are created. error: Python was built with version 6 of Visual Studio, and extensions need to be built with the same version of the compiler, but it isn't installed. Installed, and GUI has been run: the extension should build normally. Thanks, Thomas

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