Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Python Software Foundation. All rights reserved.
Copyright (c) 2000 BeOpen.com. All rights reserved.
Copyright (c) 1995-2001 Corporation for National Research Initiatives. All rights reserved.
Copyright (c) 1991-1995 Stichting Mathematisch Centrum. All rights reserved.
See the file "LICENSE" for information on the history of this software, terms & conditions for usage, and a DISCLAIMER OF ALL WARRANTIES.
This Python distribution contains no GNU General Public Licensed (GPLed) code so it may be used in proprietary projects just like prior Python distributions. There are interfaces to some GNU code but these are entirely optional.
All trademarks referenced herein are property of their respective holders.
See the file "Misc/NEWS".
Congratulations on getting this far. :-)
To start building right away (on UNIX): type "./configure" in the current directory and when it finishes, type "make". This creates an executable "./python"; to install in /usr/local, first do "su root" and then "make install".
The section `Build instructions' below is still recommended reading.
Python is an interpreted, interactive object-oriented programming language suitable (amongst other uses) for distributed application development, scripting, numeric computing and system testing. Python is often compared to Tcl, Perl, Java, JavaScript, Visual Basic or Scheme. To find out more about what Python can do for you, point your browser to http://www.python.org/.
The official tutorial is still a good place to start; see http://docs.python.org/ for online and downloadable versions, as well as a list of other introductions, and reference documentation.
There's a quickly growing set of books on Python. See http://wiki.python.org/moin/PythonBooks for a list.
All documentation is provided online in a variety of formats. In order of importance for new users: Tutorial, Library Reference, Language Reference, Extending & Embedding, and the Python/C API. The Library Reference is especially of immense value since much of Python's power is described there, including the built-in data types and functions!
All documentation is also available online at the Python web site (http://docs.python.org/, see below). It is available online for occasional reference, or can be downloaded in many formats for faster access. The documentation is downloadable in HTML, PostScript, PDF, LaTeX, and reStructuredText (2.6+) formats; the LaTeX and reStructuredText versions are primarily for documentation authors, translators, and people with special formatting requirements.
New Python releases and related technologies are published at http://www.python.org/. Come visit us!
There's also a Python community web site at http://starship.python.net/.
Read comp.lang.python, a high-volume discussion newsgroup about Python, or comp.lang.python.announce, a low-volume moderated newsgroup for Python-related announcements. These are also accessible as mailing lists: see http://www.python.org/community/lists.html for an overview of these and many other Python-related mailing lists.
Archives are accessible via the Google Groups Usenet archive; see http://groups.google.com/. The mailing lists are also archived, see http://www.python.org/community/lists.html for details.
To report or search for bugs, please use the Python Bug Tracker at http://bugs.python.org.
To submit a patch or other contribution, please use the Python Patch Manager at http://bugs.python.org. Guidelines for patch submission may be found at http://www.python.org/dev/patches/.
If you have a proposal to change Python, you may want to send an email to the comp.lang.python or python-ideas mailing lists for inital feedback. A Python Enhancement Proposal (PEP) may be submitted if your idea gains ground. All current PEPs, as well as guidelines for submitting a new PEP, are listed at http://www.python.org/dev/peps/.
For help, if you can't find it in the manuals or on the web site, it's best to post to the comp.lang.python or the Python mailing list (see above). If you specifically don't want to involve the newsgroup or mailing list, send questions to help@python.org (a group of volunteers who answer questions as they can). The newsgroup is the most efficient way to ask public questions.
Before you can build Python, you must first configure it. Fortunately, the configuration and build process has been automated for Unix and Linux installations, so all you usually have to do is type a few commands and sit back. There are some platforms where things are not quite as smooth; see the platform specific notes below. If you want to build for multiple platforms sharing the same source tree, see the section on VPATH below.
Start by running the script "./configure", which determines your system configuration and creates the Makefile. (It takes a minute or two -- please be patient!) You may want to pass options to the configure script -- see the section below on configuration options and variables. When it's done, you are ready to run make.
To build Python, you normally type "make" in the toplevel directory. If you have changed the configuration, the Makefile may have to be rebuilt. In this case you may have to run make again to correctly build your desired target. The interpreter executable is built in the top level directory.
Once you have built a Python interpreter, see the subsections below on testing and installation. If you run into trouble, see the next section.
Previous versions of Python used a manual configuration process that involved editing the file Modules/Setup. While this file still exists and manual configuration is still supported, it is rarely needed any more: almost all modules are automatically built as appropriate under guidance of the setup.py script, which is run by Make after the interpreter has been built.
See also the platform specific notes in the next section.
If you run into other trouble, see the FAQ (http://www.python.org/doc/faq) for hints on what can go wrong, and how to fix it.
If you rerun the configure script with different options, remove all object files by running "make clean" before rebuilding. Believe it or not, "make clean" sometimes helps to clean up other inexplicable problems as well. Try it before sending in a bug report!
If the configure script fails or doesn't seem to find things that should be there, inspect the config.log file.
If you get a warning for every file about the -Olimit option being no longer supported, you can ignore it. There's no foolproof way to know whether this option is needed; all we can do is test whether it is accepted without error. On some systems, e.g. older SGI compilers, it is essential for performance (specifically when compiling eval.cc, which has more basic blocks than the default limit of 1000). If the warning bothers you, edit the Makefile to remove "-Olimit 1500" from the OPT variable.
If you get failures in test_long, or sys.maxint gets set to -1, you are probably experiencing compiler bugs, usually related to optimization. This is a common problem with some versions of gcc, and some vendor-supplied compilers, which can sometimes be worked around by turning off optimization. Consider switching to stable versions (gcc 2.95.2, gcc 3.x, or contact your vendor.)
From Python 2.0 onward, all Python C code is ANSI C. Compiling using old K&R-C-only compilers is no longer possible. ANSI C compilers are available for all modern systems, either in the form of updated compilers from the vendor, or one of the free compilers (gcc).
If "make install" fails mysteriously during the "compiling the library" step, make sure that you don't have any of the PYTHONPATH or PYTHONHOME environment variables set, as they may interfere with the newly built executable which is compiling the library.
A number of features are not supported in Python 2.5 anymore. Some support code is still present, but will be removed in Python 2.6. If you still need to use current Python versions on these systems, please send a message to python-dev@python.org indicating that you volunteer to support this system. For a more detailed discussion regarding no-longer-supported and resupporting platforms, as well as a list of platforms that became or will be unsupported, see PEP 11.
More specifically, the following systems are not supported any longer:
The following systems are still supported in Python 2.5, but support will be dropped in 2.6:
Following Microsoft's closing of Extended Support for Windows 98/ME (July 11, 2006), Python 2.6 will stop supporting these platforms. Python development and maintainability becomes easier (and more reliable) when platform specific code targeting OSes with few users and no dedicated expert developers is taken out. The vendor also warns that the OS versions listed above "can expose customers to security risks" and recommends upgrade.
(Some of these may no longer apply. If you find you can build Python on these platforms without the special directions mentioned here, submit a documentation bug report to SourceForge (see Bug Reports above) so we can remove them!)
Unix platforms: If your vendor still ships (and you still use) Berkeley DB 1.85 you will need to edit Modules/Setup to build the bsddb185 module and add a line to sitecustomize.py which makes it the default. In Modules/Setup a line like
bsddb185 bsddbmodule.c
should work. (You may need to add -I, -L or -l flags to direct the
compiler and linker to your include files and libraries.)
XXX I think this next bit is out of date:
64-bit platforms: The modules audioop, and imageop don't work. The setup.py script disables them on 64-bit installations. Don't try to enable them in the Modules/Setup file. They contain code that is quite wordsize sensitive. (If you have a fix, let us know!)
Solaris: When using Sun's C compiler with threads, at least on Solaris 2.5.1, you need to add the "-mt" compiler option (the simplest way is probably to specify the compiler with this option as the "CC" environment variable when running the configure script).
When using GCC on Solaris, beware of binutils 2.13 or GCC
versions built using it. This mistakenly enables the
-zcombreloc option which creates broken shared libraries on
Solaris. binutils 2.12 works, and the binutils maintainers
are aware of the problem. Binutils 2.13.1 only partially
fixed things. It appears that 2.13.2 solves the problem
completely. This problem is known to occur with Solaris 2.7
and 2.8, but may also affect earlier and later versions of the
OS.
When the dynamic loader complains about errors finding shared
libraries, such as
ld.so.1: ./python: fatal: libstdc++.so.5: open failed:
No such file or directory
you need to first make sure that the library is available on
your system. Then, you need to instruct the dynamic loader how
to find it. You can choose any of the following strategies:
1. When compiling Python, set LD_RUN_PATH to the directories
containing missing libraries.
2. When running Python, set LD_LIBRARY_PATH to these directories.
3. Use crle(8) to extend the search path of the loader.
4. Modify the installed GCC specs file, adding -R options into the
*link: section.
The complex object fails to compile on Solaris 10 with gcc 3.4 (at
least up to 3.4.3). To work around it, define Py_HUGE_VAL as
HUGE_VAL(), e.g.:
make CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()" -I. -I$(srcdir)/Include'
./python setup.py CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()"'
Linux: A problem with threads and fork() was tracked down to a bug in the pthreads code in glibc version 2.0.5; glibc version 2.0.7 solves the problem. This causes the popen2 test to fail; problem and solution reported by Pablo Bleyer.
Red Hat Linux: Red Hat 9 built Python2.2 in UCS-4 mode and hacked Tcl to support it. To compile Python2.3 with Tkinter, you will need to pass --enable-unicode=ucs4 flag to ./configure.
There's an executable /usr/bin/python which is Python
1.5.2 on most older Red Hat installations; several key Red Hat tools
require this version. Python 2.1.x may be installed as
/usr/bin/python2. The Makefile installs Python as
/usr/local/bin/python, which may or may not take precedence
over /usr/bin/python, depending on how you have set up $PATH.
FreeBSD 3.x and probably platforms with NCurses that use libmytinfo or similar: When using cursesmodule, the linking is not done in the correct order with the defaults. Remove "-ltermcap" from the readline entry in Setup, and use as curses entry: "curses cursesmodule.c -lmytinfo -lncurses -ltermcap" - "mytinfo" (so called on FreeBSD) should be the name of the auxiliary library required on your platform. Normally, it would be linked automatically, but not necessarily in the correct order.
BSDI: BSDI versions before 4.1 have known problems with threads, which can cause strange errors in a number of modules (for instance, the 'test_signal' test script will hang forever.) Turning off threads (with --with-threads=no) or upgrading to BSDI 4.1 solves this problem.
DEC Unix: Run configure with --with-dec-threads, or with --with-threads=no if no threads are desired (threads are on by default). When using GCC, it is possible to get an internal compiler error if optimization is used. This was reported for GCC 2.7.2.3 on selectmodule.c. Manually compile the affected file without optimization to solve the problem.
DEC Ultrix: compile with GCC to avoid bugs in the native compiler, and pass SHELL=/bin/sh5 to Make when installing.
AIX: A complete overhaul of the shared library support is now in place. See Misc/AIX-NOTES for some notes on how it's done. (The optimizer bug reported at this place in previous releases has been worked around by a minimal code change.) If you get errors about pthread_* functions, during compile or during testing, try setting CC to a thread-safe (reentrant) compiler, like "cc_r". For full C++ module support, set CC="xlC_r" (or CC="xlC" without thread support).
AIX 5.3: To build a 64-bit version with IBM's compiler, I used the following:
export PATH=/usr/bin:/usr/vacpp/bin
./configure --with-gcc="xlc_r -q64" --with-cxx="xlC_r -q64" \
--disable-ipv6 AR="ar -X64"
make
HP-UX: When using threading, you may have to add -D_REENTRANT to the OPT variable in the top-level Makefile; reported by Pat Knight, this seems to make a difference (at least for HP-UX 10.20) even though pyconfig.h defines it. This seems unnecessary when using HP/UX 11 and later - threading seems to work "out of the box".
HP-UX ia64: When building on the ia64 (Itanium) platform using HP's compiler, some experience has shown that the compiler's optimiser produces a completely broken version of python (see http://www.python.org/sf/814976). To work around this, edit the Makefile and remove -O from the OPT line.
To build a 64-bit executable on an Itanium 2 system using HP's
compiler, use these environment variables:
CC=cc
CXX=aCC
BASECFLAGS="+DD64"
LDFLAGS="+DD64 -lxnet"
and call configure as:
./configure --without-gcc
then *unset* the environment variables again before running
make. (At least one of these flags causes the build to fail
if it remains set.) You still have to edit the Makefile and
remove -O from the OPT line.
HP PA-RISC 2.0: A recent bug report (http://www.python.org/sf/546117) suggests that the C compiler in this 64-bit system has bugs in the optimizer that break Python. Compiling without optimization solves the problems.
SCO: The following apply to SCO 3 only; Python builds out of the box on SCO 5 (or so we've heard).
1) Everything works much better if you add -U__STDC__ to the
defs. This is because all the SCO header files are broken.
Anything that isn't mentioned in the C standard is
conditionally excluded when __STDC__ is defined.
2) Due to the U.S. export restrictions, SCO broke the crypt
stuff out into a separate library, libcrypt_i.a so the LIBS
needed be set to:
LIBS=' -lsocket -lcrypt_i'
UnixWare: There are known bugs in the math library of the system, as well as problems in the handling of threads (calling fork in one thread may interrupt system calls in others). Therefore, test_math and tests involving threads will fail until those problems are fixed.
QNX: Chris Herborth (chrish@qnx.com) writes: configure works best if you use GNU bash; a port is available on ftp.qnx.com in /usr/free. I used the following process to build, test and install Python 1.5.x under QNX:
1) CONFIG_SHELL=/usr/local/bin/bash CC=cc RANLIB=: \
./configure --verbose --without-gcc --with-libm=""
2) edit Modules/Setup to activate everything that makes sense for
your system... tested here at QNX with the following modules:
array, audioop, binascii, cPickle, cStringIO, cmath,
crypt, curses, errno, fcntl, gdbm, grp, imageop,
_locale, math, md5, new, operator, parser, pcre,
posix, pwd, readline, regex, reop,
select, signal, socket, soundex, strop, struct,
syslog, termios, time, timing, zlib, audioop, imageop
3) make SHELL=/usr/local/bin/bash
or, if you feel the need for speed:
make SHELL=/usr/local/bin/bash OPT="-5 -Oil+nrt"
4) make SHELL=/usr/local/bin/bash test
Using GNU readline 2.2 seems to behave strangely, but I
think that's a problem with my readline 2.2 port. :-\
5) make SHELL=/usr/local/bin/bash install
If you get SIGSEGVs while running Python (I haven't yet, but
I've only run small programs and the test cases), you're
probably running out of stack; the default 32k could be a
little tight. To increase the stack size, edit the Makefile
to read: LDFLAGS = -N 48k
BeOS: See Misc/BeOS-NOTES for notes about compiling/installing Python on BeOS R3 or later. Note that only the PowerPC platform is supported for R3; both PowerPC and x86 are supported for R4.
Cray T3E: Mark Hadfield (m.hadfield@niwa.co.nz) writes: Python can be built satisfactorily on a Cray T3E but based on my experience with the NIWA T3E (2002-05-22, version 2.2.1) there are a few bugs and gotchas. For more information see a thread on comp.lang.python in May 2002 entitled "Building Python on Cray T3E".
1) Use Cray's cc and not gcc. The latter was reported not to
work by Konrad Hinsen. It may work now, but it may not.
2) To set sys.platform to something sensible, pass the
following environment variable to the configure script:
MACHDEP=unicosmk
2) Run configure with option "--enable-unicode=ucs4".
3) The Cray T3E does not support dynamic linking, so extension
modules have to be built by adding (or uncommenting) lines
in Modules/Setup. The minimum set of modules is
posix, new, _sre, unicodedata
On NIWA's vanilla T3E system the following have also been
included successfully:
_codecs, _locale, _socket, _symtable, _testcapi, _weakref
array, binascii, cmath, cPickle, crypt, cStringIO, dbm
errno, fcntl, grp, math, md5, operator, parser, pcre, pwd
regex, rotor, select, struct, strop, syslog, termios
time, timing, xreadlines
4) Once the python executable and library have been built, make
will execute setup.py, which will attempt to build remaining
extensions and link them dynamically. Each of these attempts
will fail but should not halt the make process. This is
normal.
5) Running "make test" uses a lot of resources and causes
problems on our system. You might want to try running tests
singly or in small groups.
SGI: SGI's standard "make" utility (/bin/make or /usr/bin/make) does not check whether a command actually changed the file it is supposed to build. This means that whenever you say "make" it will redo the link step. The remedy is to use SGI's much smarter "smake" utility (/usr/sbin/smake), or GNU make. If you set the first line of the Makefile to #!/usr/sbin/smake smake will be invoked by make (likewise for GNU make).
WARNING: There are bugs in the optimizer of some versions of
SGI's compilers that can cause bus errors or other strange
behavior, especially on numerical operations. To avoid this,
try building with "make OPT=".
OS/2: If you are running Warp3 or Warp4 and have IBM's VisualAge C/C++ compiler installed, just change into the pc\os2vacpp directory and type NMAKE. Threading and sockets are supported by default in the resulting binaries of PYTHON15.DLL and PYTHON.EXE.
Monterey (64-bit AIX): The current Monterey C compiler (Visual Age) uses the OBJECT_MODE={32|64} environment variable to set the compilation mode to either 32-bit or 64-bit (32-bit mode is the default). Presumably you want 64-bit compilation mode for this 64-bit OS. As a result you must first set OBJECT_MODE=64 in your environment before configuring (./configure) or building (make) Python on Monterey.
Reliant UNIX: The thread support does not compile on Reliant UNIX, and there is a (minor) problem in the configure script for that platform as well. This should be resolved in time for a future release.
MacOSX: The tests will crash on both 10.1 and 10.2 with SEGV in test_re and test_sre due to the small default stack size. If you set the stack size to 2048 before doing a "make test" the failure can be avoided. If you're using the tcsh or csh shells, use "limit stacksize 2048" and for the bash shell (the default as of OSX 10.3), use "ulimit -s 2048".
On naked Darwin you may want to add the configure option
"--disable-toolbox-glue" to disable the glue code for the Carbon
interface modules. The modules themselves are currently only built
if you add the --enable-framework option, see below.
On a clean OSX /usr/local does not exist. Do a
"sudo mkdir -m 775 /usr/local"
before you do a make install. It is probably not a good idea to
do "sudo make install" which installs everything as superuser,
as this may later cause problems when installing distutils-based
additions.
Some people have reported problems building Python after using "fink"
to install additional unix software. Disabling fink (remove all
references to /sw from your .profile or .login) should solve this.
You may want to try the configure option "--enable-framework"
which installs Python as a framework. The location can be set
as argument to the --enable-framework option (default
/Library/Frameworks). A framework install is probably needed if you
want to use any Aqua-based GUI toolkit (whether Tkinter, wxPython,
Carbon, Cocoa or anything else).
You may also want to try the configure option "--enable-universalsdk"
which builds Python as a universal binary with support for the
i386 and PPC architetures. This requires Xcode 2.1 or later to build.
See Mac/README for more information on framework and
universal builds.
Cygwin: With recent (relative to the time of writing, 2001-12-19) Cygwin installations, there are problems with the interaction of dynamic linking and fork(). This manifests itself in build failures during the execution of setup.py.
There are two workarounds that both enable Python (albeit
without threading support) to build and pass all tests on
NT/2000 (and most likely XP as well, though reports of testing
on XP would be appreciated).
The workarounds:
(a) the band-aid fix is to link the _socket module statically
rather than dynamically (which is the default).
To do this, run "./configure --with-threads=no" including any
other options you need (--prefix, etc.). Then in Modules/Setup
uncomment the lines:
#SSL=/usr/local/ssl
#_socket socketmodule.c \
# -DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
# -L$(SSL)/lib -lssl -lcrypto
and remove "local/" from the SSL variable. Finally, just run
"make"!
(b) The "proper" fix is to rebase the Cygwin DLLs to prevent
base address conflicts. Details on how to do this can be
found in the following mail:
http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
It is hoped that a version of this solution will be
incorporated into the Cygwin distribution fairly soon.
Two additional problems:
(1) Threading support should still be disabled due to a known
bug in Cygwin pthreads that causes test_threadedtempfile to
hang.
(2) The _curses module does not build. This is a known
Cygwin ncurses problem that should be resolved the next time
that this package is released.
On older versions of Cygwin, test_poll may hang and test_strftime
may fail.
The situation on 9X/Me is not accurately known at present.
Some time ago, there were reports that the following
regression tests failed:
test_pwd
test_select (hang)
test_socket
Due to the test_select hang on 9X/Me, one should run the
regression test using the following:
make TESTOPTS='-l -x test_select' test
News regarding these platforms with more recent Cygwin
versions would be appreciated!
Windows: When executing Python scripts on the command line using file type associations (i.e. starting "script.py" instead of "python script.py"), redirects may not work unless you set a specific registry key. See the Knowledge Base article http://support.microsoft.com/kb/321788.
Beginning with Python version 2.3, the PyBsddb package http://pybsddb.sf.net/ was adopted into Python as the bsddb package, exposing a set of package-level functions which provide backwards-compatible behavior. Only versions 3.3 through 4.4 of Sleepycat's libraries provide the necessary API, so older versions aren't supported through this interface. The old bsddb module has been retained as bsddb185, though it is not built by default. Users wishing to use it will have to tweak Modules/Setup to build it. The dbm module will still be built against the Sleepycat libraries if other preferred alternatives (ndbm, gdbm) are not found.
To build the sqlite3 module, you'll need the sqlite3 or libsqlite3 packages installed, including the header files. Many modern operating systems distribute the headers in a separate package to the library - often it will be the same name as the main package, but with a -dev or -devel suffix.
The version of pysqlite2 that's including in Python needs sqlite3 3.0.8 or later. setup.py attempts to check that it can find a correct version.
As of Python 2.0, threads are enabled by default. If you wish to compile without threads, or if your thread support is broken, pass the --with-threads=no switch to configure. Unfortunately, on some platforms, additional compiler and/or linker options are required for threads to work properly. Below is a table of those options, collected by Bill Janssen. We would love to automate this process more, but the information below is not enough to write a patch for the configure.in file, so manual intervention is required. If you patch the configure.in file and are confident that the patch works, please send in the patch. (Don't bother patching the configure script itself -- it is regenerated each time the configure.in file changes.)
Compiler switches for threads .............................
The definition of _REENTRANT should be configured automatically, if that does not work on your system, or if _REENTRANT is defined incorrectly, please report that as a bug.
OS/Compiler/threads Switches for use with threads
(POSIX is draft 10, DCE is draft 4) compile & link
SunOS 5.{1-5}/{gcc,SunPro cc}/solaris -mt
SunOS 5.5/{gcc,SunPro cc}/POSIX (nothing)
DEC OSF/1 3.x/cc/DCE -threads
(butenhof@zko.dec.com)
Digital UNIX 4.x/cc/DCE -threads
(butenhof@zko.dec.com)
Digital UNIX 4.x/cc/POSIX -pthread
(butenhof@zko.dec.com)
AIX 4.1.4/cc_r/d7 (nothing)
(buhrt@iquest.net)
AIX 4.1.4/cc_r4/DCE (nothing)
(buhrt@iquest.net)
IRIX 6.2/cc/POSIX (nothing)
(robertl@cwi.nl)
Linker (ld) libraries and flags for threads ...........................................
OS/threads Libraries/switches for use with threads
SunOS 5.{1-5}/solaris -lthread
SunOS 5.5/POSIX -lpthread
DEC OSF/1 3.x/DCE -lpthreads -lmach -lc_r -lc
(butenhof@zko.dec.com)
Digital UNIX 4.x/DCE -lpthreads -lpthread -lmach -lexc -lc
(butenhof@zko.dec.com)
Digital UNIX 4.x/POSIX -lpthread -lmach -lexc -lc
(butenhof@zko.dec.com)
AIX 4.1.4/{draft7,DCE} (nothing)
(buhrt@iquest.net)
IRIX 6.2/POSIX -lpthread
(jph@emilia.engr.sgi.com)
Starting with Python 2.3, the majority of the interpreter can be built into a shared library, which can then be used by the interpreter executable, and by applications embedding Python. To enable this feature, configure with --enable-shared.
If you enable this feature, the same object files will be used to create a static library. In particular, the static library will contain object files using position-independent code (PIC) on platforms where PIC flags are needed for the shared library.
Starting with Python 2.1, the setup.py script at the top of the source distribution attempts to detect which modules can be built and automatically compiles them. Autodetection doesn't always work, so you can still customize the configuration by editing the Modules/Setup file; but this should be considered a last resort. The rest of this section only applies if you decide to edit the Modules/Setup file. You also need this to enable static linking of certain modules (which is needed to enable profiling on some systems).
This file is initially copied from Setup.dist by the configure script; if it does not exist yet, create it by copying Modules/Setup.dist yourself (configure will never overwrite it). Never edit Setup.dist -- always edit Setup or Setup.local (see below). Read the comments in the file for information on what kind of edits are allowed. When you have edited Setup in the Modules directory, the interpreter will automatically be rebuilt the next time you run make (in the toplevel directory).
Many useful modules can be built on any Unix system, but some optional modules can't be reliably autodetected. Often the quickest way to determine whether a particular module works or not is to see if it will build: enable it in Setup, then if you get compilation or link errors, disable it -- you're either missing support or need to adjust the compilation and linking parameters for that module.
On SGI IRIX, there are modules that interface to many SGI specific system libraries, e.g. the GL library and the audio hardware. These modules will not be built by the setup.py script.
In addition to the file Setup, you can also edit the file Setup.local. (the makesetup script processes both). You may find it more convenient to edit Setup.local and leave Setup alone. Then, when installing a new Python version, you can copy your old Setup.local file.
If you want or need to change the optimization/debugging options for the C compiler, assign to the OPT variable on the toplevel make command; e.g. "make OPT=-g" will build a debugging version of Python on most platforms. The default is OPT=-O; a value for OPT in the environment when the configure script is run overrides this default (likewise for CC; and the initial value for LIBS is used as the base set of libraries to link with).
When compiling with GCC, the default value of OPT will also include the -Wall and -Wstrict-prototypes options.
Additional debugging code to help debug memory management problems can be enabled by using the --with-pydebug option to the configure script.
For flags that change binary compatibility, use the EXTRA_CFLAGS variable.
If you want C profiling turned on, the easiest way is to run configure with the CC environment variable to the necessary compiler invocation. For example, on Linux, this works for profiling using gprof(1):
CC="gcc -pg" ./configure
Note that on Linux, gprof apparently does not work for shared libraries. The Makefile/Setup mechanism can be used to compile and link most extension modules statically.
For C coverage checking using gcov, run "make coverage". This will build a Python binary with profiling activated, and a ".gcno" and ".gcda" file for every source file compiled with that option. With the built binary, now run the code whose coverage you want to check. Then, you can see coverage statistics for each individual source file by running gcov, e.g.
gcov -o Modules zlibmodule
This will create a "zlibmodule.c.gcov" file in the current directory containing coverage info for that source file.
This works only for source files statically compiled into the executable; use the Makefile/Setup mechanism to compile and link extension modules you want to coverage-check statically.
To test the interpreter, type "make test" in the top-level directory. This runs the test set twice (once with no compiled files, once with the compiled files left by the previous test run). The test set produces some output. You can generally ignore the messages about skipped tests due to optional features which can't be imported. If a message is printed about a failed test or a traceback or core dump is produced, something is wrong. On some Linux systems (those that are not yet using glibc 6), test_strftime fails due to a non-standard implementation of strftime() in the C library. Please ignore this, or upgrade to glibc version 6.
IMPORTANT: If the tests fail and you decide to mail a bug report, don't include the output of "make test". It is useless. Run the failing test manually, as follows:
./python ./Lib/test/test_whatever.py
(substituting the top of the source tree for '.' if you built in a different directory). This runs the test in verbose mode.
To install the Python binary, library modules, shared library modules (see below), include files, configuration files, and the manual page, just type
make install
This will install all platform-independent files in subdirectories of
the directory given with the --prefix option to configure or to the
prefix' Make variable (default /usr/local). All binary and other platform-specific files will be installed in subdirectories if the directory given by --exec-prefix or the
exec_prefix' Make variable
(defaults to the --prefix directory) is given.
If DESTDIR is set, it will be taken as the root directory of the installation, and files will be installed into $(DESTDIR)$(prefix), $(DESTDIR)$(exec_prefix), etc.
All subdirectories created will have Python's version number in their
name, e.g. the library modules are installed in
"/usr/local/lib/python