1This is Python version 2.7.18
2=============================
3
4Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
52012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Python Software Foundation. All
6rights reserved.
7
8Copyright (c) 2000 BeOpen.com.
9All rights reserved.
10
11Copyright (c) 1995-2001 Corporation for National Research Initiatives.
12All rights reserved.
13
14Copyright (c) 1991-1995 Stichting Mathematisch Centrum.
15All rights reserved.
16
17
18License information
19-------------------
20
21See the file "LICENSE" for information on the history of this
22software, terms & conditions for usage, and a DISCLAIMER OF ALL
23WARRANTIES.
24
25This Python distribution contains no GNU General Public Licensed
26(GPLed) code so it may be used in proprietary projects just like prior
27Python distributions. There are interfaces to some GNU code but these
28are entirely optional.
29
30All trademarks referenced herein are property of their respective
31holders.
32
33
34What's new in this release?
35---------------------------
36
37See the file "Misc/NEWS".
38
39
40If you don't read instructions
41------------------------------
42
43Congratulations on getting this far. :-)
44
45To start building right away (on UNIX): type "./configure" in the
46current directory and when it finishes, type "make". This creates an
47executable "./python"; to install in /usr/local, first do "su root"
48and then "make install".
49
50The section `Build instructions' below is still recommended reading.
51
52
53What is Python anyway?
54----------------------
55
56Python is an interpreted, interactive object-oriented programming
57language suitable (amongst other uses) for distributed application
58development, scripting, numeric computing and system testing. Python
59is often compared to Tcl, Perl, Java, JavaScript, Visual Basic or
60Scheme. To find out more about what Python can do for you, point your
61browser to http://www.python.org/.
62
63
64How do I learn Python?
65----------------------
66
67The official tutorial is still a good place to start; see
68http://docs.python.org/ for online and downloadable versions, as well
69as a list of other introductions, and reference documentation.
70
71There's a quickly growing set of books on Python. See
72http://wiki.python.org/moin/PythonBooks for a list.
73
74
75Documentation
76-------------
77
78All documentation is provided online in a variety of formats. In
79order of importance for new users: Tutorial, Library Reference,
80Language Reference, Extending & Embedding, and the Python/C API. The
81Library Reference is especially of immense value since much of
82Python's power is described there, including the built-in data types
83and functions!
84
85All documentation is also available online at the Python web site
86(http://docs.python.org/, see below). It is available online for occasional
87reference, or can be downloaded in many formats for faster access. The
88documentation is downloadable in HTML, PostScript, PDF, LaTeX, and
89reStructuredText (2.6+) formats; the LaTeX and reStructuredText versions are
90primarily for documentation authors, translators, and people with special
91formatting requirements.
92
93If you would like to contribute to the development of Python, relevant
94documentation is available at:
95
96 http://docs.python.org/devguide/
97
98For information about building Python's documentation, refer to Doc/README.txt.
99
100
101Web sites
102---------
103
104New Python releases and related technologies are published at
105http://www.python.org/. Come visit us!
106
107
108Newsgroups and Mailing Lists
109----------------------------
110
111Read comp.lang.python, a high-volume discussion newsgroup about
112Python, or comp.lang.python.announce, a low-volume moderated newsgroup
113for Python-related announcements. These are also accessible as
114mailing lists: see http://www.python.org/community/lists/ for an
115overview of these and many other Python-related mailing lists.
116
117Archives are accessible via the Google Groups Usenet archive; see
118http://groups.google.com/. The mailing lists are also archived, see
119http://www.python.org/community/lists/ for details.
120
121
122Bug reports
123-----------
124
125To report or search for bugs, please use the Python Bug
126Tracker at http://bugs.python.org/.
127
128
129Patches and contributions
130-------------------------
131
132To submit a patch or other contribution, please use the Python Patch
133Manager at http://bugs.python.org/. Guidelines
134for patch submission may be found at http://www.python.org/dev/patches/.
135
136If you have a proposal to change Python, you may want to send an email to the
137comp.lang.python or python-ideas mailing lists for inital feedback. A Python
138Enhancement Proposal (PEP) may be submitted if your idea gains ground. All
139current PEPs, as well as guidelines for submitting a new PEP, are listed at
140http://www.python.org/dev/peps/.
141
142
143Questions
144---------
145
146For help, if you can't find it in the manuals or on the web site, it's
147best to post to the comp.lang.python or the Python mailing list (see
148above). If you specifically don't want to involve the newsgroup or
149mailing list, send questions to help@python.org (a group of volunteers
150who answer questions as they can). The newsgroup is the most
151efficient way to ask public questions.
152
153
154Build instructions
155==================
156
157Before you can build Python, you must first configure it.
158Fortunately, the configuration and build process has been automated
159for Unix and Linux installations, so all you usually have to do is
160type a few commands and sit back. There are some platforms where
161things are not quite as smooth; see the platform specific notes below.
162If you want to build for multiple platforms sharing the same source
163tree, see the section on VPATH below.
164
165Start by running the script "./configure", which determines your
166system configuration and creates the Makefile. (It takes a minute or
167two -- please be patient!) You may want to pass options to the
168configure script -- see the section below on configuration options and
169variables. When it's done, you are ready to run make.
170
171To build Python, you normally type "make" in the toplevel directory.
172If you have changed the configuration, the Makefile may have to be
173rebuilt. In this case, you may have to run make again to correctly
174build your desired target. The interpreter executable is built in the
175top level directory.
176
177To get an optimized build of Python, "configure --enable-optimizations" before
178you run make. This sets the default make targets up to enable Profile Guided
179Optimization (PGO) and may be used to auto-enable Link Time Optimization (LTO)
180on some platforms. For more details, see the sections bellow.
181
182Once you have built a Python interpreter, see the subsections below on
183testing and installation. If you run into trouble, see the next
184section.
185
186Previous versions of Python used a manual configuration process that
187involved editing the file Modules/Setup. While this file still exists
188and manual configuration is still supported, it is rarely needed any
189more: almost all modules are automatically built as appropriate under
190guidance of the setup.py script, which is run by Make after the
191interpreter has been built.
192
193
194Profile Guided Optimization
195---------------------------
196
197PGO takes advantage of recent versions of the GCC or Clang compilers.
198If ran, "make profile-opt" will do several steps.
199
200First, the entire Python directory is cleaned of temporary files that
201may have resulted in a previous compilation.
202
203Then, an instrumented version of the interpreter is built, using suitable
204compiler flags for each flavour. Note that this is just an intermediary
205step and the binary resulted after this step is not good for real life
206workloads, as it has profiling instructions embedded inside.
207
208After this instrumented version of the interpreter is built, the Makefile
209will automatically run a training workload. This is necessary in order to
210profile the interpreter execution. Note also that any output, both stdout
211and stderr, that may appear at this step is suppressed.
212
213Finally, the last step is to rebuild the interpreter, using the information
214collected in the previous one. The end result will be a Python binary
215that is optimized and suitable for distribution or production installation.
216
217
218Link Time Optimization
219----------------------
220
221Enabled via configure's --with-lto flag. LTO takes advantages of recent
222compiler toolchains ability to optimize across the otherwise arbitrary .o file
223boundary when building final executables or shared libraries for additional
224performance gains.
225
226
227Troubleshooting
228---------------
229
230See also the platform specific notes in the next section.
231
232If you run into other trouble, see the FAQ
233(http://www.python.org/doc/faq/) for hints on what can go wrong, and
234how to fix it.
235
236If you rerun the configure script with different options, remove all
237object files by running "make clean" before rebuilding. Believe it or
238not, "make clean" sometimes helps to clean up other inexplicable
239problems as well. Try it before sending in a bug report!
240
241If the configure script fails or doesn't seem to find things that
242should be there, inspect the config.log file.
243
244If you get a warning for every file about the -Olimit option being no
245longer supported, you can ignore it. There's no foolproof way to know
246whether this option is needed; all we can do is test whether it is
247accepted without error. On some systems, e.g. older SGI compilers, it
248is essential for performance (specifically when compiling ceval.c,
249which has more basic blocks than the default limit of 1000). If the
250warning bothers you, edit the Makefile to remove "-Olimit 1500" from
251the OPT variable.
252
253If you get failures in test_long, or sys.maxint gets set to -1, you
254are probably experiencing compiler bugs, usually related to
255optimization. This is a common problem with some versions of gcc, and
256some vendor-supplied compilers, which can sometimes be worked around
257by turning off optimization. Consider switching to stable versions
258(gcc 2.95.2, gcc 3.x, or contact your vendor.)
259
260From Python 2.0 onward, all Python C code is ANSI C. Compiling using
261old K&R-C-only compilers is no longer possible. ANSI C compilers are
262available for all modern systems, either in the form of updated
263compilers from the vendor, or one of the free compilers (gcc).
264
265If "make install" fails mysteriously during the "compiling the library"
266step, make sure that you don't have any of the PYTHONPATH or PYTHONHOME
267environment variables set, as they may interfere with the newly built
268executable which is compiling the library.
269
270Unsupported systems
271-------------------
272
273A number of systems are not supported in Python 2.7 anymore. Some
274support code is still present, but will be removed in later versions.
275If you still need to use current Python versions on these systems,
276please send a message to python-dev@python.org indicating that you
277volunteer to support this system. For a more detailed discussion
278regarding no-longer-supported and resupporting platforms, as well
279as a list of platforms that became or will be unsupported, see PEP 11.
280
281More specifically, the following systems are not supported any
282longer:
283- SunOS 4
284- DYNIX
285- dgux
286- Minix
287- NeXT
288- Irix 4 and --with-sgi-dl
289- Linux 1
290- Systems defining __d6_pthread_create (configure.ac)
291- Systems defining PY_PTHREAD_D4, PY_PTHREAD_D6,
292 or PY_PTHREAD_D7 in thread_pthread.h
293- Systems using --with-dl-dld
294- Systems using --without-universal-newlines
295- MacOS 9
296- Systems using --with-wctype-functions
297- Win9x, WinME
298
299
300Platform specific notes
301-----------------------
302
303(Some of these may no longer apply. If you find you can build Python
304on these platforms without the special directions mentioned here,
305submit a documentation bug report to SourceForge (see Bug Reports
306above) so we can remove them!)
307
308Unix platforms: If your vendor still ships (and you still use) Berkeley DB
309 1.85 you will need to edit Modules/Setup to build the bsddb185
310 module and add a line to sitecustomize.py which makes it the
311 default. In Modules/Setup a line like
312
313 bsddb185 bsddbmodule.c
314
315 should work. (You may need to add -I, -L or -l flags to direct the
316 compiler and linker to your include files and libraries.)
317
318XXX I think this next bit is out of date:
319
32064-bit platforms: The modules audioop, and imageop don't work.
321 The setup.py script disables them on 64-bit installations.
322 Don't try to enable them in the Modules/Setup file. They
323 contain code that is quite wordsize sensitive. (If you have a
324 fix, let us know!)
325
326Solaris: When using Sun's C compiler with threads, at least on Solaris
327 2.5.1, you need to add the "-mt" compiler option (the simplest
328 way is probably to specify the compiler with this option as
329 the "CC" environment variable when running the configure
330 script).
331
332 When using GCC on Solaris, beware of binutils 2.13 or GCC
333 versions built using it. This mistakenly enables the
334 -zcombreloc option which creates broken shared libraries on
335 Solaris. binutils 2.12 works, and the binutils maintainers
336 are aware of the problem. Binutils 2.13.1 only partially
337 fixed things. It appears that 2.13.2 solves the problem
338 completely. This problem is known to occur with Solaris 2.7
339 and 2.8, but may also affect earlier and later versions of the
340 OS.
341
342 When the dynamic loader complains about errors finding shared
343 libraries, such as
344
345 ld.so.1: ./python: fatal: libstdc++.so.5: open failed:
346 No such file or directory
347
348 you need to first make sure that the library is available on
349 your system. Then, you need to instruct the dynamic loader how
350 to find it. You can choose any of the following strategies:
351
352 1. When compiling Python, set LD_RUN_PATH to the directories
353 containing missing libraries.
354 2. When running Python, set LD_LIBRARY_PATH to these directories.
355 3. Use crle(8) to extend the search path of the loader.
356 4. Modify the installed GCC specs file, adding -R options into the
357 *link: section.
358
359 The complex object fails to compile on Solaris 10 with gcc 3.4 (at
360 least up to 3.4.3). To work around it, define Py_HUGE_VAL as
361 HUGE_VAL(), e.g.:
362
363 make CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()" -I. -I$(srcdir)/Include'
364 ./python setup.py CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()"'
365
366Linux: A problem with threads and fork() was tracked down to a bug in
367 the pthreads code in glibc version 2.0.5; glibc version 2.0.7
368 solves the problem. This causes the popen2 test to fail;
369 problem and solution reported by Pablo Bleyer.
370
371Red Hat Linux: Red Hat 9 built Python2.2 in UCS-4 mode and hacked
372 Tcl to support it. To compile Python2.3 with Tkinter, you will
373 need to pass --enable-unicode=ucs4 flag to ./configure.
374
375 There's an executable /usr/bin/python which is Python
376 1.5.2 on most older Red Hat installations; several key Red Hat tools
377 require this version. Python 2.1.x may be installed as
378 /usr/bin/python2. The Makefile installs Python as
379 /usr/local/bin/python, which may or may not take precedence
380 over /usr/bin/python, depending on how you have set up $PATH.
381
382FreeBSD 3.x and probably platforms with NCurses that use libmytinfo or
383 similar: When using cursesmodule, the linking is not done in
384 the correct order with the defaults. Remove "-ltermcap" from
385 the readline entry in Setup, and use as curses entry: "curses
386 cursesmodule.c -lmytinfo -lncurses -ltermcap" - "mytinfo" (so
387 called on FreeBSD) should be the name of the auxiliary library
388 required on your platform. Normally, it would be linked
389 automatically, but not necessarily in the correct order.
390
391BSDI: BSDI versions before 4.1 have known problems with threads,
392 which can cause strange errors in a number of modules (for
393 instance, the 'test_signal' test script will hang forever.)
394 Turning off threads (with --with-threads=no) or upgrading to
395 BSDI 4.1 solves this problem.
396
397DEC Unix: Run configure with --with-dec-threads, or with
398 --with-threads=no if no threads are desired (threads are on by
399 default). When using GCC, it is possible to get an internal
400 compiler error if optimization is used. This was reported for
401 GCC 2.7.2.3 on selectmodule.c. Manually compile the affected
402 file without optimization to solve the problem.
403
404DEC Ultrix: compile with GCC to avoid bugs in the native compiler,
405 and pass SHELL=/bin/sh5 to Make when installing.
406
407AIX: A complete overhaul of the shared library support is now in
408 place. See Misc/AIX-NOTES for some notes on how it's done.
409 (The optimizer bug reported at this place in previous releases
410 has been worked around by a minimal code change.) If you get
411 errors about pthread_* functions, during compile or during
412 testing, try setting CC to a thread-safe (reentrant) compiler,
413 like "cc_r". For full C++ module support, set CC="xlC_r" (or
414 CC="xlC" without thread support).
415
416AIX 5.3: To build a 64-bit version with IBM's compiler, I used the
417 following:
418
419 export PATH=/usr/bin:/usr/vacpp/bin
420 ./configure --with-gcc="xlc_r -q64" --with-cxx="xlC_r -q64" \
421 --disable-ipv6 AR="ar -X64"
422 make
423
424HP-UX: When using threading, you may have to add -D_REENTRANT to the
425 OPT variable in the top-level Makefile; reported by Pat Knight,
426 this seems to make a difference (at least for HP-UX 10.20)
427 even though pyconfig.h defines it. This seems unnecessary when
428 using HP/UX 11 and later - threading seems to work "out of the
429 box".
430
431HP-UX ia64: When building on the ia64 (Itanium) platform using HP's
432 compiler, some experience has shown that the compiler's
433 optimiser produces a completely broken version of python
434 (see http://bugs.python.org/814976). To work around this,
435 edit the Makefile and remove -O from the OPT line.
436
437 To build a 64-bit executable on an Itanium 2 system using HP's
438 compiler, use these environment variables:
439
440 CC=cc
441 CXX=aCC
442 BASECFLAGS="+DD64"
443 LDFLAGS="+DD64 -lxnet"
444
445 and call configure as:
446
447 ./configure --without-gcc
448
449 then *unset* the environment variables again before running
450 make. (At least one of these flags causes the build to fail
451 if it remains set.) You still have to edit the Makefile and
452 remove -O from the OPT line.
453
454HP PA-RISC 2.0: A recent bug report (http://bugs.python.org/546117)
455 suggests that the C compiler in this 64-bit system has bugs
456 in the optimizer that break Python. Compiling without
457 optimization solves the problems.
458
459SCO: The following apply to SCO 3 only; Python builds out of the box
460 on SCO 5 (or so we've heard).
461
462 1) Everything works much better if you add -U__STDC__ to the
463 defs. This is because all the SCO header files are broken.
464 Anything that isn't mentioned in the C standard is
465 conditionally excluded when __STDC__ is defined.
466
467 2) Due to the U.S. export restrictions, SCO broke the crypt
468 stuff out into a separate library, libcrypt_i.a so the LIBS
469 needed be set to:
470
471 LIBS=' -lsocket -lcrypt_i'
472
473UnixWare: There are known bugs in the math library of the system, as well as
474 problems in the handling of threads (calling fork in one
475 thread may interrupt system calls in others). Therefore, test_math and
476 tests involving threads will fail until those problems are fixed.
477
478QNX: Chris Herborth (chrish@qnx.com) writes:
479 configure works best if you use GNU bash; a port is available on
480 ftp.qnx.com in /usr/free. I used the following process to build,
481 test and install Python 1.5.x under QNX:
482
483 1) CONFIG_SHELL=/usr/local/bin/bash CC=cc RANLIB=: \
484 ./configure --verbose --without-gcc --with-libm=""
485
486 2) edit Modules/Setup to activate everything that makes sense for
487 your system... tested here at QNX with the following modules:
488
489 array, audioop, binascii, cPickle, cStringIO, cmath,
490 crypt, curses, errno, fcntl, gdbm, grp, imageop,
491 _locale, math, md5, new, operator, parser, pcre,
492 posix, pwd, readline, regex, reop,
493 select, signal, socket, soundex, strop, struct,
494 syslog, termios, time, timing, zlib, audioop, imageop
495
496 3) make SHELL=/usr/local/bin/bash
497
498 or, if you feel the need for speed:
499
500 make SHELL=/usr/local/bin/bash OPT="-5 -Oil+nrt"
501
502 4) make SHELL=/usr/local/bin/bash test
503
504 Using GNU readline 2.2 seems to behave strangely, but I
505 think that's a problem with my readline 2.2 port. :-\
506
507 5) make SHELL=/usr/local/bin/bash install
508
509 If you get SIGSEGVs while running Python (I haven't yet, but
510 I've only run small programs and the test cases), you're
511 probably running out of stack; the default 32k could be a
512 little tight. To increase the stack size, edit the Makefile
513 to read: LDFLAGS = -N 48k
514
515BeOS: See Misc/BeOS-NOTES for notes about compiling/installing
516 Python on BeOS R3 or later. Note that only the PowerPC
517 platform is supported for R3; both PowerPC and x86 are
518 supported for R4.
519
520Cray T3E: Mark Hadfield (m.hadfield@niwa.co.nz) writes:
521 Python can be built satisfactorily on a Cray T3E but based on
522 my experience with the NIWA T3E (2002-05-22, version 2.2.1)
523 there are a few bugs and gotchas. For more information see a
524 thread on comp.lang.python in May 2002 entitled "Building
525 Python on Cray T3E".
526
527 1) Use Cray's cc and not gcc. The latter was reported not to
528 work by Konrad Hinsen. It may work now, but it may not.
529
530 2) To set sys.platform to something sensible, pass the
531 following environment variable to the configure script:
532
533 MACHDEP=unicosmk
534
535 2) Run configure with option "--enable-unicode=ucs4".
536
537 3) The Cray T3E does not support dynamic linking, so extension
538 modules have to be built by adding (or uncommenting) lines
539 in Modules/Setup. The minimum set of modules is
540
541 posix, new, _sre, unicodedata
542
543 On NIWA's vanilla T3E system the following have also been
544 included successfully:
545
546 _codecs, _locale, _socket, _symtable, _testcapi, _weakref
547 array, binascii, cmath, cPickle, crypt, cStringIO, dbm
548 errno, fcntl, grp, math, md5, operator, parser, pcre, pwd
549 regex, rotor, select, struct, strop, syslog, termios
550 time, timing, xreadlines
551
552 4) Once the python executable and library have been built, make
553 will execute setup.py, which will attempt to build remaining
554 extensions and link them dynamically. Each of these attempts
555 will fail but should not halt the make process. This is
556 normal.
557
558 5) Running "make test" uses a lot of resources and causes
559 problems on our system. You might want to try running tests
560 singly or in small groups.
561
562SGI: SGI's standard "make" utility (/bin/make or /usr/bin/make)
563 does not check whether a command actually changed the file it
564 is supposed to build. This means that whenever you say "make"
565 it will redo the link step. The remedy is to use SGI's much
566 smarter "smake" utility (/usr/sbin/smake), or GNU make. If
567 you set the first line of the Makefile to #!/usr/sbin/smake
568 smake will be invoked by make (likewise for GNU make).
569
570 WARNING: There are bugs in the optimizer of some versions of
571 SGI's compilers that can cause bus errors or other strange
572 behavior, especially on numerical operations. To avoid this,
573 try building with "make OPT=".
574
575OS/2: If you are running Warp3 or Warp4 and have IBM's VisualAge C/C++
576 compiler installed, just change into the pc\os2vacpp directory
577 and type NMAKE. Threading and sockets are supported by default
578 in the resulting binaries of PYTHON15.DLL and PYTHON.EXE.
579
580Reliant UNIX: The thread support does not compile on Reliant UNIX, and
581 there is a (minor) problem in the configure script for that
582 platform as well. This should be resolved in time for a
583 future release.
584
585macOS: Building a complete Python installation requires the use of various
586 additional third-party libraries, depending on your build platform and
587 configure options. Not all standard library modules are buildable or
588 useable on all platforms. Refer to the "Install Dependencies" section
589 section of the "Developer Guide" for current detailed information on
590 dependencies for macOS:
591 https://devguide.python.org/setup/#install-dependencies
592
593 On macOS, there are additional configure and build options related
594 to macOS framework and universal builds. Refer to Mac/README.rst.
595
596 The tests will crash on both 10.1 and 10.2 with SEGV in
597 test_re and test_sre due to the small default stack size. If
598 you set the stack size to 2048 before doing a "make test" the
599 failure can be avoided. If you're using the tcsh or csh shells,
600 use "limit stacksize 2048" and for the bash shell (the default
601 as of macOS 10.3), use "ulimit -s 2048".
602
603 On naked Darwin you may want to add the configure option
604 "--disable-toolbox-glue" to disable the glue code for the Carbon
605 interface modules. The modules themselves are currently only built
606 if you add the --enable-framework option, see below.
607
608 On a clean macOS /usr/local does not exist. Do a
609 "sudo mkdir -m 775 /usr/local"
610 before you do a make install. It is probably not a good idea to
611 do "sudo make install" which installs everything as superuser,
612 as this may later cause problems when installing distutils-based
613 additions.
614
615 Some people have reported problems building Python after using "fink"
616 to install additional unix software. Disabling fink (remove all
617 references to /sw from your .profile or .login) should solve this.
618
619Cygwin: With recent (relative to the time of writing, 2001-12-19)
620 Cygwin installations, there are problems with the interaction
621 of dynamic linking and fork(). This manifests itself in build
622 failures during the execution of setup.py.
623
624 There are two workarounds that both enable Python (albeit
625 without threading support) to build and pass all tests on
626 NT/2000 (and most likely XP as well, though reports of testing
627 on XP would be appreciated).
628
629 The workarounds:
630
631 (a) the band-aid fix is to link the _socket module statically
632 rather than dynamically (which is the default).
633
634 To do this, run "./configure --with-threads=no" including any
635 other options you need (--prefix, etc.). Then in Modules/Setup
636 uncomment the lines:
637
638 #SSL=/usr/local/ssl
639 #_socket socketmodule.c \
640 # -DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
641 # -L$(SSL)/lib -lssl -lcrypto
642
643 and remove "local/" from the SSL variable. Finally, just run
644 "make"!
645
646 (b) The "proper" fix is to rebase the Cygwin DLLs to prevent
647 base address conflicts. Details on how to do this can be
648 found in the following mail:
649
650 http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
651
652 It is hoped that a version of this solution will be
653 incorporated into the Cygwin distribution fairly soon.
654
655 Two additional problems:
656
657 (1) Threading support should still be disabled due to a known
658 bug in Cygwin pthreads that causes test_threadedtempfile to
659 hang.
660
661 (2) The _curses module does not build. This is a known
662 Cygwin ncurses problem that should be resolved the next time
663 that this package is released.
664
665 On older versions of Cygwin, test_poll may hang and test_strftime
666 may fail.
667
668 The situation on 9X/Me is not accurately known at present.
669 Some time ago, there were reports that the following
670 regression tests failed:
671
672 test_pwd
673 test_select (hang)
674 test_socket
675
676 Due to the test_select hang on 9X/Me, one should run the
677 regression test using the following:
678
679 make TESTOPTS='-l -x test_select' test
680
681 News regarding these platforms with more recent Cygwin
682 versions would be appreciated!
683
684Windows: When executing Python scripts on the command line using file type
685 associations (i.e. starting "script.py" instead of "python script.py"),
686 redirects may not work unless you set a specific registry key. See
687 the Knowledge Base article <http://support.microsoft.com/kb/321788>.
688
689
690Configuring the bsddb and dbm modules
691-------------------------------------
692
693Beginning with Python version 2.3, the PyBsddb package
694<http://pybsddb.sf.net/> was adopted into Python as the bsddb package,
695exposing a set of package-level functions which provide
696backwards-compatible behavior. Only versions 3.3 through 4.4 of
697Sleepycat's libraries provide the necessary API, so older versions
698aren't supported through this interface. The old bsddb module has
699been retained as bsddb185, though it is not built by default. Users
700wishing to use it will have to tweak Modules/Setup to build it. The
701dbm module will still be built against the Sleepycat libraries if
702other preferred alternatives (ndbm, gdbm) are not found.
703
704Building the sqlite3 module
705---------------------------
706
707To build the sqlite3 module, you'll need the sqlite3 or libsqlite3
708packages installed, including the header files. Many modern operating
709systems distribute the headers in a separate package to the library -
710often it will be the same name as the main package, but with a -dev or
711-devel suffix.
712
713The version of pysqlite2 that's including in Python needs sqlite3 3.0.8
714or later. setup.py attempts to check that it can find a correct version.
715
716Configuring threads
717-------------------
718
719As of Python 2.0, threads are enabled by default. If you wish to
720compile without threads, or if your thread support is broken, pass the
721--with-threads=no switch to configure. Unfortunately, on some
722platforms, additional compiler and/or linker options are required for
723threads to work properly. Below is a table of those options,
724collected by Bill Janssen. We would love to automate this process
725more, but the information below is not enough to write a patch for the
726configure.ac file, so manual intervention is required. If you patch
727the configure.ac file and are confident that the patch works, please
728send in the patch. (Don't bother patching the configure script itself
729-- it is regenerated each time the configure.ac file changes.)
730
731Compiler switches for threads
732.............................
733
734The definition of _REENTRANT should be configured automatically, if
735that does not work on your system, or if _REENTRANT is defined
736incorrectly, please report that as a bug.
737
738 OS/Compiler/threads Switches for use with threads
739 (POSIX is draft 10, DCE is draft 4) compile & link
740
741 SunOS 5.{1-5}/{gcc,SunPro cc}/solaris -mt
742 SunOS 5.5/{gcc,SunPro cc}/POSIX (nothing)
743 DEC OSF/1 3.x/cc/DCE -threads
744 (butenhof@zko.dec.com)
745 Digital UNIX 4.x/cc/DCE -threads
746 (butenhof@zko.dec.com)
747 Digital UNIX 4.x/cc/POSIX -pthread
748 (butenhof@zko.dec.com)
749 AIX 4.1.4/cc_r/d7 (nothing)
750 (buhrt@iquest.net)
751 AIX 4.1.4/cc_r4/DCE (nothing)
752 (buhrt@iquest.net)
753 IRIX 6.2/cc/POSIX (nothing)
754 (robertl@cwi.nl)
755
756
757Linker (ld) libraries and flags for threads
758...........................................
759
760 OS/threads Libraries/switches for use with threads
761
762 SunOS 5.{1-5}/solaris -lthread
763 SunOS 5.5/POSIX -lpthread
764 DEC OSF/1 3.x/DCE -lpthreads -lmach -lc_r -lc
765 (butenhof@zko.dec.com)
766 Digital UNIX 4.x/DCE -lpthreads -lpthread -lmach -lexc -lc
767 (butenhof@zko.dec.com)
768 Digital UNIX 4.x/POSIX -lpthread -lmach -lexc -lc
769 (butenhof@zko.dec.com)
770 AIX 4.1.4/{draft7,DCE} (nothing)
771 (buhrt@iquest.net)
772 IRIX 6.2/POSIX -lpthread
773 (jph@emilia.engr.sgi.com)
774
775
776Building a shared libpython
777---------------------------
778
779Starting with Python 2.3, the majority of the interpreter can be built
780into a shared library, which can then be used by the interpreter
781executable, and by applications embedding Python. To enable this feature,
782configure with --enable-shared.
783
784If you enable this feature, the same object files will be used to create
785a static library. In particular, the static library will contain object
786files using position-independent code (PIC) on platforms where PIC flags
787are needed for the shared library.
788
789
790Configuring additional built-in modules
791---------------------------------------
792
793Starting with Python 2.1, the setup.py script at the top of the source
794distribution attempts to detect which modules can be built and
795automatically compiles them. Autodetection doesn't always work, so
796you can still customize the configuration by editing the Modules/Setup
797file; but this should be considered a last resort. The rest of this
798section only applies if you decide to edit the Modules/Setup file.
799You also need this to enable static linking of certain modules (which
800is needed to enable profiling on some systems).
801
802This file is initially copied from Setup.dist by the configure script;
803if it does not exist yet, create it by copying Modules/Setup.dist
804yourself (configure will never overwrite it). Never edit Setup.dist
805-- always edit Setup or Setup.local (see below). Read the comments in
806the file for information on what kind of edits are allowed. When you
807have edited Setup in the Modules directory, the interpreter will
808automatically be rebuilt the next time you run make (in the toplevel
809directory).
810
811Many useful modules can be built on any Unix system, but some optional
812modules can't be reliably autodetected. Often the quickest way to
813determine whether a particular module works or not is to see if it
814will build: enable it in Setup, then if you get compilation or link
815errors, disable it -- you're either missing support or need to adjust
816the compilation and linking parameters for that module.
817
818On SGI IRIX, there are modules that interface to many SGI specific
819system libraries, e.g. the GL library and the audio hardware. These
820modules will not be built by the setup.py script.
821
822In addition to the file Setup, you can also edit the file Setup.local.
823(the makesetup script processes both). You may find it more
824convenient to edit Setup.local and leave Setup alone. Then, when
825installing a new Python version, you can copy your old Setup.local
826file.
827
828
829Setting the optimization/debugging options
830------------------------------------------
831
832If you want or need to change the optimization/debugging options for
833the C compiler, assign to the OPT variable on the toplevel make
834command; e.g. "make OPT=-g" will build a debugging version of Python
835on most platforms. The default is OPT=-O; a value for OPT in the
836environment when the configure script is run overrides this default
837(likewise for CC; and the initial value for LIBS is used as the base
838set of libraries to link with).
839
840When compiling with GCC, the default value of OPT will also include
841the -Wall and -Wstrict-prototypes options.
842
843Additional debugging code to help debug memory management problems can
844be enabled by using the --with-pydebug option to the configure script.
845
846For flags that change binary compatibility, use the EXTRA_CFLAGS
847variable.
848
849
850Profiling
851---------
852
853If you want C profiling turned on, the easiest way is to run configure
854with the CC environment variable to the necessary compiler
855invocation. For example, on Linux, this works for profiling using
856gprof(1):
857
858 CC="gcc -pg" ./configure
859
860Note that on Linux, gprof apparently does not work for shared
861libraries. The Makefile/Setup mechanism can be used to compile and
862link most extension modules statically.
863
864
865Coverage checking
866-----------------
867
868For C coverage checking using gcov, run "make coverage". This will
869build a Python binary with profiling activated, and a ".gcno" and
870".gcda" file for every source file compiled with that option. With
871the built binary, now run the code whose coverage you want to check.
872Then, you can see coverage statistics for each individual source file
873by running gcov, e.g.
874
875 gcov -o Modules zlibmodule
876
877This will create a "zlibmodule.c.gcov" file in the current directory
878containing coverage info for that source file.
879
880This works only for source files statically compiled into the
881executable; use the Makefile/Setup mechanism to compile and link
882extension modules you want to coverage-check statically.
883
884
885Testing
886-------
887
888To test the interpreter, type "make test" in the top-level directory.
889This runs the test set twice (once with no compiled files, once with
890the compiled files left by the previous test run). The test set
891produces some output. You can generally ignore the messages about
892skipped tests due to optional features which can't be imported.
893If a message is printed about a failed test or a traceback or core
894dump is produced, something is wrong. On some Linux systems (those
895that are not yet using glibc 6), test_strftime fails due to a
896non-standard implementation of strftime() in the C library. Please
897ignore this, or upgrade to glibc version 6.
898
899By default, tests are prevented from overusing resources like disk space and
900memory. To enable these tests, run "make testall".
901
902IMPORTANT: If the tests fail and you decide to mail a bug report,
903*don't* include the output of "make test". It is useless. Run the
904failing test manually, as follows:
905
906 ./python Lib/test/regrtest.py -v test_whatever
907
908(substituting the top of the source tree for '.' if you built in a
909different directory). This runs the test in verbose mode.
910
911
912Installing
913----------
914
915To install the Python binary, library modules, shared library modules
916(see below), include files, configuration files, and the manual page,
917just type
918
919 make install
920
921This will install all platform-independent files in subdirectories of
922the directory given with the --prefix option to configure or to the
923`prefix' Make variable (default /usr/local). All binary and other
924platform-specific files will be installed in subdirectories if the
925directory given by --exec-prefix or the `exec_prefix' Make variable
926(defaults to the --prefix directory) is given.
927
928If DESTDIR is set, it will be taken as the root directory of the
929installation, and files will be installed into $(DESTDIR)$(prefix),
930$(DESTDIR)$(exec_prefix), etc.
931
932All subdirectories created will have Python's version number in their
933name, e.g. the library modules are installed in
934"/usr/local/lib/python<version>/" by default, where <version> is the
935<major>.<minor> release number (e.g. "2.1"). The Python binary is
936installed as "python<version>" and a hard link named "python" is
937created. The only file not installed with a version number in its
938name is the manual page, installed as "/usr/local/man/man1/python.1"
939by default.
940
941If you want to install multiple versions of Python see the section below
942entitled "Installing multiple versions".
943
944The only thing you may have to install manually is the Python mode for
945Emacs found in Misc/python-mode.el. (But then again, more recent
946versions of Emacs may already have it.) Follow the instructions that
947came with Emacs for installation of site-specific files.
948
949
950Installing multiple versions
951----------------------------
952
953On Unix and Mac systems if you intend to install multiple versions of Python
954using the same installation prefix (--prefix argument to the configure
955script) you must take care that your primary python executable is not
956overwritten by the installation of a different version. All files and
957directories installed using "make altinstall" contain the major and minor
958version and can thus live side-by-side. "make install" also creates
959${prefix}/bin/python which refers to ${prefix}/bin/pythonX.Y. If you intend
960to install multiple versions using the same prefix you must decide which
961version (if any) is your "primary" version. Install that version using
962"make install". Install all other versions using "make altinstall".
963
964For example, if you want to install Python 2.5, 2.6 and 3.0 with 2.6 being
965the primary version, you would execute "make install" in your 2.6 build
966directory and "make altinstall" in the others.
967
968
969Configuration options and variables
970-----------------------------------
971
972Some special cases are handled by passing options to the configure
973script.
974
975WARNING: if you rerun the configure script with different options, you
976must run "make clean" before rebuilding. Exceptions to this rule:
977after changing --prefix or --exec-prefix, all you need to do is remove
978Modules/getpath.o.
979
980--with(out)-gcc: The configure script uses gcc (the GNU C compiler) if
981 it finds it. If you don't want this, or if this compiler is
982 installed but broken on your platform, pass the option
983 --without-gcc. You can also pass "CC=cc" (or whatever the
984 name of the proper C compiler is) in the environment, but the
985 advantage of using --without-gcc is that this option is
986 remembered by the config.status script for its --recheck
987 option.
988
989--prefix, --exec-prefix: If you want to install the binaries and the
990 Python library somewhere else than in /usr/local/{bin,lib},
991 you can pass the option --prefix=DIRECTORY; the interpreter
992 binary will be installed as DIRECTORY/bin/python and the
993 library files as DIRECTORY/lib/python/*. If you pass
994 --exec-prefix=DIRECTORY (as well) this overrides the
995 installation prefix for architecture-dependent files (like the
996 interpreter binary). Note that --prefix=DIRECTORY also
997 affects the default module search path (sys.path), when
998 Modules/config.c is compiled. Passing make the option
999 prefix=DIRECTORY (and/or exec_prefix=DIRECTORY) overrides the
1000 prefix set at configuration time; this may be more convenient
1001 than re-running the configure script if you change your mind
1002 about the install prefix.
1003
1004--with-readline: This option is no longer supported. GNU
1005 readline is automatically enabled by setup.py when present.
1006
1007--with-threads: On most Unix systems, you can now use multiple
1008 threads, and support for this is enabled by default. To
1009 disable this, pass --with-threads=no. If the library required
1010 for threads lives in a peculiar place, you can use
1011 --with-thread=DIRECTORY. IMPORTANT: run "make clean" after
1012 changing (either enabling or disabling) this option, or you
1013 will get link errors! Note: for DEC Unix use
1014 --with-dec-threads instead.
1015
1016--with-sgi-dl: On SGI IRIX 4, dynamic loading of extension modules is
1017 supported by the "dl" library by Jack Jansen, which is
1018 ftp'able from ftp://ftp.cwi.nl/pub/dynload/dl-1.6.tar.Z.
1019 This is enabled (after you've ftp'ed and compiled the dl
1020 library) by passing --with-sgi-dl=DIRECTORY where DIRECTORY
1021 is the absolute pathname of the dl library. (Don't bother on
1022 IRIX 5, it already has dynamic linking using SunOS style
1023 shared libraries.) THIS OPTION IS UNSUPPORTED.
1024
1025--with-dl-dld: Dynamic loading of modules is rumored to be supported
1026 on some other systems: VAX (Ultrix), Sun3 (SunOS 3.4), Sequent
1027 Symmetry (Dynix), and Atari ST. This is done using a
1028 combination of the GNU dynamic loading package
1029 (ftp://ftp.cwi.nl/pub/dynload/dl-dld-1.1.tar.Z) and an
1030 emulation of the SGI dl library mentioned above (the emulation
1031 can be found at
1032 ftp://ftp.cwi.nl/pub/dynload/dld-3.2.3.tar.Z). To
1033 enable this, ftp and compile both libraries, then call
1034 configure, passing it the option
1035 --with-dl-dld=DL_DIRECTORY,DLD_DIRECTORY where DL_DIRECTORY is
1036 the absolute pathname of the dl emulation library and
1037 DLD_DIRECTORY is the absolute pathname of the GNU dld library.
1038 (Don't bother on SunOS 4 or 5, they already have dynamic
1039 linking using shared libraries.) THIS OPTION IS UNSUPPORTED.
1040
1041--with-libm, --with-libc: It is possible to specify alternative
1042 versions for the Math library (default -lm) and the C library
1043 (default the empty string) using the options
1044 --with-libm=STRING and --with-libc=STRING, respectively. For
1045 example, if your system requires that you pass -lc_s to the C
1046 compiler to use the shared C library, you can pass
1047 --with-libc=-lc_s. These libraries are passed after all other
1048 libraries, the C library last.
1049
1050--with-libs='libs': Add 'libs' to the LIBS that the python interpreter
1051 is linked against.
1052
1053--with-cxx-main=<compiler>: If you plan to use C++ extension modules,
1054 then -- on some platforms -- you need to compile python's main()
1055 function with the C++ compiler. With this option, make will use
1056 <compiler> to compile main() *and* to link the python executable.
1057 It is likely that the resulting executable depends on the C++
1058 runtime library of <compiler>. (The default is --without-cxx-main.)
1059
1060 There are platforms that do not require you to build Python
1061 with a C++ compiler in order to use C++ extension modules.
1062 E.g., x86 Linux with ELF shared binaries and GCC 3.x, 4.x is such
1063 a platform. We recommend that you configure Python
1064 --without-cxx-main on those platforms because a mismatch
1065 between the C++ compiler version used to build Python and to
1066 build a C++ extension module is likely to cause a crash at
1067 runtime.
1068
1069 The Python installation also stores the variable CXX that
1070 determines, e.g., the C++ compiler distutils calls by default
1071 to build C++ extensions. If you set CXX on the configure command
1072 line to any string of non-zero length, then configure won't
1073 change CXX. If you do not preset CXX but pass
1074 --with-cxx-main=<compiler>, then configure sets CXX=<compiler>.
1075 In all other cases, configure looks for a C++ compiler by
1076 some common names (c++, g++, gcc, CC, cxx, cc++, cl) and sets
1077 CXX to the first compiler it finds. If it does not find any
1078 C++ compiler, then it sets CXX="".
1079
1080 Similarly, if you want to change the command used to link the
1081 python executable, then set LINKCC on the configure command line.
1082
1083
1084--with-pydebug: Enable additional debugging code to help track down
1085 memory management problems. This allows printing a list of all
1086 live objects when the interpreter terminates.
1087
1088--with(out)-universal-newlines: enable reading of text files with
1089 foreign newline convention (default: enabled). In other words,
1090 any of \r, \n or \r\n is acceptable as end-of-line character.
1091 If enabled import and execfile will automatically accept any newline
1092 in files. Python code can open a file with open(file, 'U') to
1093 read it in universal newline mode. THIS OPTION IS UNSUPPORTED.
1094
1095--with-tsc: Profile using the Pentium timestamping counter (TSC).
1096
1097--with-system-ffi: Build the _ctypes extension module using an ffi
1098 library installed on the system.
1099
1100--with-dbmliborder=db1:db2:...: Specify the order that backends for the
1101 dbm extension are checked. Valid value is a colon separated string
1102 with the backend names `ndbm', `gdbm' and `bdb'.
1103
1104Building for multiple architectures (using the VPATH feature)
1105-------------------------------------------------------------
1106
1107If your file system is shared between multiple architectures, it
1108usually is not necessary to make copies of the sources for each
1109architecture you want to support. If the make program supports the
1110VPATH feature, you can create an empty build directory for each
1111architecture, and in each directory run the configure script (on the
1112appropriate machine with the appropriate options). This creates the
1113necessary subdirectories and the Makefiles therein. The Makefiles
1114contain a line VPATH=... which points to a directory containing the
1115actual sources. (On SGI systems, use "smake -J1" instead of "make" if
1116you use VPATH -- don't try gnumake.)
1117
1118For example, the following is all you need to build a minimal Python
1119in /usr/tmp/python (assuming ~guido/src/python is the toplevel
1120directory and you want to build in /usr/tmp/python):
1121
1122 $ mkdir /usr/tmp/python
1123 $ cd /usr/tmp/python
1124 $ ~guido/src/python/configure
1125 [...]
1126 $ make
1127 [...]
1128 $
1129
1130Note that configure copies the original Setup file to the build
1131directory if it finds no Setup file there. This means that you can
1132edit the Setup file for each architecture independently. For this
1133reason, subsequent changes to the original Setup file are not tracked
1134automatically, as they might overwrite local changes. To force a copy
1135of a changed original Setup file, delete the target Setup file. (The
1136makesetup script supports multiple input files, so if you want to be
1137fancy you can change the rules to create an empty Setup.local if it
1138doesn't exist and run it with arguments $(srcdir)/Setup Setup.local;
1139however this assumes that you only need to add modules.)
1140
1141Also note that you can't use a workspace for VPATH and non VPATH builds. The
1142object files left behind by one version confuses the other.
1143
1144
1145Building on non-UNIX systems
1146----------------------------
1147
1148For Windows (2000/NT/ME/98/95), assuming you have MS VC++ 7.1, the
1149project files are in PCbuild, the workspace is pcbuild.dsw. See
1150PCbuild\readme.txt for detailed instructions.
1151
1152For other non-Unix Windows compilers, in particular MS VC++ 6.0 and
1153for OS/2, enter the directory "PC" and read the file "readme.txt".
1154
1155For the Mac, a separate source distribution will be made available,
1156for use with the CodeWarrior compiler. If you are interested in Mac
1157development, join the PythonMac Special Interest Group
1158(http://www.python.org/sigs/pythonmac-sig/, or send email to
1159pythonmac-sig-request@python.org).
1160
1161Of course, there are also binary distributions available for these
1162platforms -- see http://www.python.org/.
1163
1164To port Python to a new non-UNIX system, you will have to fake the
1165effect of running the configure script manually (for Mac and PC, this
1166has already been done for you). A good start is to copy the file
1167pyconfig.h.in to pyconfig.h and edit the latter to reflect the actual
1168configuration of your system. Most symbols must simply be defined as
11691 only if the corresponding feature is present and can be left alone
1170otherwise; however the *_t type symbols must be defined as some
1171variant of int if they need to be defined at all.
1172
1173For all platforms, it's important that the build arrange to define the
1174preprocessor symbol NDEBUG on the compiler command line in a release
1175build of Python (else assert() calls remain in the code, hurting
1176release-build performance). The Unix, Windows and Mac builds already
1177do this.
1178
1179
1180Miscellaneous issues
1181====================
1182
1183Emacs mode
1184----------
1185
1186There's an excellent Emacs editing mode for Python code; see the file
1187Misc/python-mode.el. Originally written by the famous Tim Peters, it is now
1188maintained by the equally famous Barry Warsaw. The latest version, along with
1189various other contributed Python-related Emacs goodies, is online at
1190http://launchpad.net/python-mode/.
1191
1192
1193Tkinter
1194-------
1195
1196The setup.py script automatically configures this when it detects a
1197usable Tcl/Tk installation. This requires Tcl/Tk version 8.0 or
1198higher.
1199
1200For more Tkinter information, see the Tkinter Resource page:
1201http://www.python.org/topics/tkinter/
1202
1203There are demos in the Demo/tkinter directory.
1204
1205Note that there's a Python module called "Tkinter" (capital T) which
1206lives in Lib/lib-tk/Tkinter.py, and a C module called "_tkinter"
1207(lower case t and leading underscore) which lives in
1208Modules/_tkinter.c. Demos and normal Tk applications import only the
1209Python Tkinter module -- only the latter imports the C _tkinter
1210module. In order to find the C _tkinter module, it must be compiled
1211and linked into the Python interpreter -- the setup.py script does
1212this. In order to find the Python Tkinter module, sys.path must be
1213set correctly -- normal installation takes care of this.
1214
1215
1216Distribution structure
1217----------------------
1218
1219Most subdirectories have their own README files. Most files have
1220comments.
1221
1222Demo/ Demonstration scripts, modules and programs
1223Doc/ Documentation sources (reStructuredText)
1224Grammar/ Input for the parser generator
1225Include/ Public header files
1226LICENSE Licensing information
1227Lib/ Python library modules
1228Mac/ Macintosh specific resources
1229Makefile.pre.in Source from which config.status creates the Makefile.pre
1230Misc/ Miscellaneous useful files
1231Modules/ Implementation of most built-in modules
1232Objects/ Implementation of most built-in object types
1233PC/ Files specific to PC ports (DOS, Windows, OS/2)
1234PCbuild/ Build directory for Microsoft Visual C++
1235Parser/ The parser and tokenizer and their input handling
1236Python/ The byte-compiler and interpreter
1237README The file you're reading now
1238RISCOS/ Files specific to RISC OS port
1239Tools/ Some useful programs written in Python
1240pyconfig.h.in Source from which pyconfig.h is created (GNU autoheader output)
1241configure Configuration shell script (GNU autoconf output)
1242configure.ac Configuration specification (input for GNU autoconf)
1243install-sh Shell script used to install files
1244setup.py Python script used to build extension modules
1245
1246The following files will (may) be created in the toplevel directory by
1247the configuration and build processes:
1248
1249Makefile Build rules
1250Makefile.pre Build rules before running Modules/makesetup
1251buildno Keeps track of the build number
1252config.cache Cache of configuration variables
1253pyconfig.h Configuration header
1254config.log Log from last configure run
1255config.status Status from last run of the configure script
1256getbuildinfo.o Object file from Modules/getbuildinfo.c
1257libpython<version>.a The library archive
1258python The executable interpreter
1259reflog.txt Output from running the regression suite with the -R flag
1260tags, TAGS Tags files for vi and Emacs
1261
1262
1263That's all, folks!
1264------------------
1265
1266
1267--Guido van Rossum (home page: http://www.python.org/~guido/)
1268