Hello
> Does anyone have an complete example of a C file with a C function
> that gets turned into a Python module callable from a Python function?
yes, kind of.
> Hopefully, Macintosh based.
Unfortunately, no.
I am sending am example of a C function callable as a Python module. I
apologise for sending attachment to the list and I hope you can extract
the files ok.
I built it from the examples in the Extending Python, as you will notice
there is a lot of things copied from there.
Just follow the short instructions on the Makefile.pre.in an the run
test_it.py.
I will need to run it on a Mac, but for the time being, I am still
learning my way around.
Regards
Margarida
# Universal Unix Makefile for Python extensions
# =============================================
# Short Instructions
# ------------------
# 1. Build and install Python (1.5 or newer).
# 2. "make -f Makefile.pre.in boot"
# 3. "make"
# You should now have a shared library.
# Long Instructions
# -----------------
# Build *and install* the basic Python 1.5 distribution. See the
# Python README for instructions. (This version of Makefile.pre.in
# only withs with Python 1.5, alpha 3 or newer.)
# Create a file Setup.in for your extension. This file follows the
# format of the Modules/Setup.in file; see the instructions there.
# For a simple module called "spam" on file "spammodule.c", it can
# contain a single line:
# spam spammodule.c
# You can build as many modules as you want in the same directory --
# just have a separate line for each of them in the Setup.in file.
# If you want to build your extension as a shared library, insert a
# line containing just the string
# *shared*
# at the top of your Setup.in file.
# Note that the build process copies Setup.in to Setup, and then works
# with Setup. It doesn't overwrite Setup when Setup.in is changed, so
# while you're in the process of debugging your Setup.in file, you may
# want to edit Setup instead, and copy it back to Setup.in later.
# (All this is done so you can distribute your extension easily and
# someone else can select the modules they actually want to build by
# commenting out lines in the Setup file, without editing the
# original. Editing Setup is also used to specify nonstandard
# locations for include or library files.)
# Copy this file (Misc/Makefile.pre.in) to the directory containing
# your extension.
# Run "make -f Makefile.pre.in boot". This creates Makefile
# (producing Makefile.pre and sedscript as intermediate files) and
# config.c, incorporating the values for sys.prefix, sys.exec_prefix
# and sys.version from the installed Python binary. For this to work,
# the python binary must be on your path. If this fails, try
# make -f Makefile.pre.in Makefile VERSION=1.5 installdir=<prefix>
# where <prefix> is the prefix used to install Python for installdir
# (and possibly similar for exec_installdir=<exec_prefix>).
# Note: "make boot" implies "make clobber" -- it assumes that when you
# bootstrap you may have changed platforms so it removes all previous
# output files.
# If you are building your extension as a shared library (your
# Setup.in file starts with *shared*), run "make" or "make sharedmods"
# to build the shared library files. If you are building a statically
# linked Python binary (the only solution of your platform doesn't
# support shared libraries, and sometimes handy if you want to
# distribute or install the resulting Python binary), run "make
# python".
# Note: Each time you edit Makefile.pre.in or Setup, you must run
# "make Makefile" before running "make".
# Hint: if you want to use VPATH, you can start in an empty
# subdirectory and say (e.g.):
# make -f ../Makefile.pre.in boot srcdir=.. VPATH=..
# === Bootstrap variables (edited through "make boot") ===
# The prefix used by "make inclinstall libainstall" of core python
installdir= /usr/local
# The exec_prefix used by the same
exec_installdir=$(installdir)
# Source directory and VPATH in case you want to use VPATH.
# (You will have to edit these two lines yourself -- there is no
# automatic support as the Makefile is not generated by
# config.status.)
srcdir= .
VPATH= .
# === Variables that you may want to customize (rarely) ===
# (Static) build target
TARGET= python
# Installed python binary (used only by boot target)
PYTHON= python
# Add more -I and -D options here
CFLAGS= $(OPT) -I$(INCLUDEPY) -I$(EXECINCLUDEPY) $(DEFS)
# These two variables can be set in Setup to merge extensions.
# See example[23].
BASELIB=
BASESETUP=
# === Variables set by makesetup ===
MODOBJS= _MODOBJS_
MODLIBS= _MODLIBS_
# === Definitions added by makesetup ===
# === Variables from configure (through sedscript) ===
VERSION= @VERSION@
CC= @CC@
LINKCC= @LINKCC@
SGI_ABI= @SGI_ABI@
OPT= @OPT@
LDFLAGS= @LDFLAGS@
LDLAST= @LDLAST@
DEFS= @DEFS@
LIBS= @LIBS@
LIBM= @LIBM@
LIBC= @LIBC@
RANLIB= @RANLIB@
MACHDEP= @MACHDEP@
SO= @SO@
LDSHARED= @LDSHARED@
CCSHARED= @CCSHARED@
LINKFORSHARED= @LINKFORSHARED@
#@SET_CCC@
# Install prefix for architecture-independent files
prefix= /usr/local
# Install prefix for architecture-dependent files
exec_prefix= $(prefix)
# Uncomment the following two lines for AIX
#LINKCC= $(LIBPL)/makexp_aix $(LIBPL)/python.exp "" $(LIBRARY); $(PURIFY) $(CC)
#LDSHARED= $(LIBPL)/ld_so_aix $(CC) -bI:$(LIBPL)/python.exp
# === Fixed definitions ===
# Shell used by make (some versions default to the login shell, which is bad)
SHELL= /bin/sh
# Expanded directories
BINDIR= $(exec_installdir)/bin
LIBDIR= $(exec_prefix)/lib
MANDIR= $(installdir)/man
INCLUDEDIR= $(installdir)/include
SCRIPTDIR= $(prefix)/lib
# Detailed destination directories
BINLIBDEST= $(LIBDIR)/python$(VERSION)
LIBDEST= $(SCRIPTDIR)/python$(VERSION)
INCLUDEPY= $(INCLUDEDIR)/python$(VERSION)
EXECINCLUDEPY= $(exec_installdir)/include/python$(VERSION)
LIBP= $(exec_installdir)/lib/python$(VERSION)
DESTSHARED= $(BINLIBDEST)/site-packages
LIBPL= $(LIBP)/config
PYTHONLIBS= $(LIBPL)/libpython$(VERSION).a
MAKESETUP= $(LIBPL)/makesetup
MAKEFILE= $(LIBPL)/Makefile
CONFIGC= $(LIBPL)/config.c
CONFIGCIN= $(LIBPL)/config.c.in
SETUP= $(LIBPL)/Setup.thread $(LIBPL)/Setup.local $(LIBPL)/Setup
SYSLIBS= $(LIBM) $(LIBC)
ADDOBJS= $(LIBPL)/python.o config.o
# Portable install script (configure doesn't always guess right)
INSTALL= $(LIBPL)/install-sh -c
# Shared libraries must be installed with executable mode on some systems;
# rather than figuring out exactly which, we always give them executable mode.
# Also, making them read-only seems to be a good idea...
INSTALL_SHARED= ${INSTALL} -m 555
# === Fixed rules ===
# Default target. This builds shared libraries only
default: sharedmods
# Build everything
all: static sharedmods
# Build shared libraries from our extension modules
sharedmods: $(SHAREDMODS)
# Build a static Python binary containing our extension modules
static: $(TARGET)
$(TARGET): $(ADDOBJS) lib.a $(PYTHONLIBS) Makefile $(BASELIB)
$(LINKCC) $(LDFLAGS) $(LINKFORSHARED) \
$(ADDOBJS) lib.a $(PYTHONLIBS) \
$(LINKPATH) $(BASELIB) $(MODLIBS) $(LIBS) $(SYSLIBS) \
-o $(TARGET) $(LDLAST)
install: sharedmods
if test ! -d $(DESTSHARED) ; then \
mkdir $(DESTSHARED) ; else true ; fi
-for i in X $(SHAREDMODS); do \
if test $$i != X; \
then $(INSTALL_SHARED) $$i $(DESTSHARED)/$$i; \
fi; \
done
# Build the library containing our extension modules
lib.a: $(MODOBJS)
-rm -f lib.a
ar cr lib.a $(MODOBJS)
-$(RANLIB) lib.a
# This runs makesetup *twice* to use the BASESETUP definition from Setup
config.c Makefile: Makefile.pre Setup $(BASESETUP) $(MAKESETUP)
$(MAKESETUP) \
-m Makefile.pre -c $(CONFIGCIN) Setup -n $(BASESETUP) $(SETUP)
$(MAKE) -f Makefile do-it-again
# Internal target to run makesetup for the second time
do-it-again:
$(MAKESETUP) \
-m Makefile.pre -c $(CONFIGCIN) Setup -n $(BASESETUP) $(SETUP)
# Make config.o from the config.c created by makesetup
config.o: config.c
$(CC) $(CFLAGS) -c config.c
# Setup is copied from Setup.in *only* if it doesn't yet exist
Setup:
cp $(srcdir)/Setup.in Setup
# Make the intermediate Makefile.pre from Makefile.pre.in
Makefile.pre: Makefile.pre.in sedscript
sed -f sedscript $(srcdir)/Makefile.pre.in >Makefile.pre
# Shortcuts to make the sed arguments on one line
P=prefix
E=exec_prefix
H=Generated automatically from Makefile.pre.in by sedscript.
L=LINKFORSHARED
# Make the sed script used to create Makefile.pre from Makefile.pre.in
sedscript: $(MAKEFILE)
sed -n \
-e '1s/.*/1i\\/p' \
-e '2s%.*%# $H%p' \
-e '/^VERSION=/s/^VERSION=[ ]*\(.*\)/s%@VERSION[@]%\1%/p' \
-e '/^CC=/s/^CC=[ ]*\(.*\)/s%@CC[@]%\1%/p' \
-e '/^CCC=/s/^CCC=[ ]*\(.*\)/s%#@SET_CCC[@]%CCC=\1%/p' \
-e '/^LINKCC=/s/^LINKCC=[ ]*\(.*\)/s%@LINKCC[@]%\1%/p' \
-e '/^OPT=/s/^OPT=[ ]*\(.*\)/s%@OPT[@]%\1%/p' \
-e '/^LDFLAGS=/s/^LDFLAGS=[ ]*\(.*\)/s%@LDFLAGS[@]%\1%/p' \
-e '/^LDLAST=/s/^LDLAST=[ ]*\(.*\)/s%@LDLAST[@]%\1%/p' \
-e '/^DEFS=/s/^DEFS=[ ]*\(.*\)/s%@DEFS[@]%\1%/p' \
-e '/^LIBS=/s/^LIBS=[ ]*\(.*\)/s%@LIBS[@]%\1%/p' \
-e '/^LIBM=/s/^LIBM=[ ]*\(.*\)/s%@LIBM[@]%\1%/p' \
-e '/^LIBC=/s/^LIBC=[ ]*\(.*\)/s%@LIBC[@]%\1%/p' \
-e '/^RANLIB=/s/^RANLIB=[ ]*\(.*\)/s%@RANLIB[@]%\1%/p' \
-e '/^MACHDEP=/s/^MACHDEP=[ ]*\(.*\)/s%@MACHDEP[@]%\1%/p' \
-e '/^SO=/s/^SO=[ ]*\(.*\)/s%@SO[@]%\1%/p' \
-e '/^LDSHARED=/s/^LDSHARED=[ ]*\(.*\)/s%@LDSHARED[@]%\1%/p' \
-e '/^CCSHARED=/s/^CCSHARED=[ ]*\(.*\)/s%@CCSHARED[@]%\1%/p' \
-e '/^SGI_ABI=/s/^SGI_ABI=[ ]*\(.*\)/s%@SGI_ABI[@]%\1%/p' \
-e '/^$L=/s/^$L=[ ]*\(.*\)/s%@$L[@]%\1%/p' \
-e '/^$P=/s/^$P=\(.*\)/s%^$P=.*%$P=\1%/p' \
-e '/^$E=/s/^$E=\(.*\)/s%^$E=.*%$E=\1%/p' \
$(MAKEFILE) >sedscript
echo "/^#@SET_CCC@/d" >>sedscript
echo "/^installdir=/s%=.*%= $(installdir)%" >>sedscript
echo "/^exec_installdir=/s%=.*%=$(exec_installdir)%" >>sedscript
echo "/^srcdir=/s%=.*%= $(srcdir)%" >>sedscript
echo "/^VPATH=/s%=.*%= $(VPATH)%" >>sedscript
echo "/^LINKPATH=/s%=.*%= $(LINKPATH)%" >>sedscript
echo "/^BASELIB=/s%=.*%= $(BASELIB)%" >>sedscript
echo "/^BASESETUP=/s%=.*%= $(BASESETUP)%" >>sedscript
# Bootstrap target
boot: clobber
VERSION=`$(PYTHON) -c "import sys; print sys.version[:3]"`; \
installdir=`$(PYTHON) -c "import sys; print sys.prefix"`; \
exec_installdir=`$(PYTHON) -c "import sys; print sys.exec_prefix"`; \
$(MAKE) -f $(srcdir)/Makefile.pre.in VPATH=$(VPATH) srcdir=$(srcdir) \
VERSION=$$VERSION \
installdir=$$installdir \
exec_installdir=$$exec_installdir \
Makefile
# Handy target to remove intermediate files and backups
clean:
-rm -f *.o *~
# Handy target to remove everything that is easily regenerated
clobber: clean
-rm -f *.a tags TAGS config.c Makefile.pre $(TARGET) sedscript
-rm -f *.so *.sl so_locations
# Handy target to remove everything you don't want to distribute
distclean: clobber
-rm -f Makefile Setup
*shared*
example example_module.c
#include "Python.h"
#include <stdio.h>
/***********************************************************************
29/Fev/00 - Margarida Madeira
***********************************************************************/
static PyObject *example_estimator(self, args, keywds)
PyObject *self;
PyObject *args;
PyObject *keywds;
{
char *cWin;
int iSize;
int iStep;
int sts;
static char *kwlist[] = {"cWin", "iSize", "iStep", NULL};
if (!PyArg_ParseTupleAndKeywords(args, keywds, "cii", kwlist,
&cWin, &iSize, &iStep))
return NULL;
printf(" Function called with: %c, %i and %i \n",
cWin, iSize, iStep);
sts = iSize;
return Py_BuildValue("i", sts);
}
static PyObject *ExampleError;
static PyMethodDef ExampleMethods[] = {
{"estimator", example_estimator, METH_VARARGS|METH_KEYWORDS},
{NULL, NULL} };
void initexample()
{
PyObject *m, *d;
/* Create the module and add functions */
m = Py_InitModule("example", ExampleMethods);
d = PyModule_GetDict(m);
ExampleError = PyErr_NewException("example.error", NULL, NULL);
PyDict_SetItemString(d, "Error", ExampleError);
}
#!/usr/bin/env python
import sys
import example # loads the examplemodule.so
res = example.estimator('F', 3, 30) # Calls the function with the arguments
