adding missing python macro

m4/python.m4

@@ -0,0 +1,62 @@
+## this one is commonly used with AM_PATH_PYTHONDIR ...
+dnl AM_CHECK_PYMOD(MODNAME [,SYMBOL [,ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]]])
+dnl Check if a module containing a given symbol is visible to python.
+AC_DEFUN(AM_CHECK_PYMOD,
+[AC_REQUIRE([AM_PATH_PYTHON])
+py_mod_var=`echo $1['_']$2 | sed 'y%./+-%__p_%'`
+AC_MSG_CHECKING(for ifelse([$2],[],,[$2 in ])python module $1)
+AC_CACHE_VAL(py_cv_mod_$py_mod_var, [
+ifelse([$2],[], [prog="
+import sys
+try:
+        import $1
+except ImportError:
+        sys.exit(1)
+except:
+        sys.exit(0)
+sys.exit(0)"], [prog="
+import $1
+$1.$2"])
+if $PYTHON -c "$prog" 1>&AC_FD_CC 2>&AC_FD_CC
+  then
+    eval "py_cv_mod_$py_mod_var=yes"
+  else
+    eval "py_cv_mod_$py_mod_var=no"
+  fi
+])
+py_val=`eval "echo \`echo '$py_cv_mod_'$py_mod_var\`"`
+if test "x$py_val" != xno; then
+  AC_MSG_RESULT(yes)
+  ifelse([$3], [],, [$3
+])dnl
+else
+  AC_MSG_RESULT(no)
+  ifelse([$4], [],, [$4
+])dnl
+fi
+])
+
+dnl a macro to check for ability to create python extensions
+dnl  AM_CHECK_PYTHON_HEADERS([ACTION-IF-POSSIBLE], [ACTION-IF-NOT-POSSIBLE])
+dnl function also defines PYTHON_INCLUDES
+AC_DEFUN([AM_CHECK_PYTHON_HEADERS],
+[AC_REQUIRE([AM_PATH_PYTHON])
+AC_MSG_CHECKING(for headers required to compile python extensions)
+dnl deduce PYTHON_INCLUDES
+py_prefix=`$PYTHON -c "import sys; print sys.prefix"`
+py_exec_prefix=`$PYTHON -c "import sys; print sys.exec_prefix"`
+PYTHON_INCLUDES="-I${py_prefix}/include/python${PYTHON_VERSION}"
+if test "$py_prefix" != "$py_exec_prefix"; then
+  PYTHON_INCLUDES="$PYTHON_INCLUDES -I${py_exec_prefix}/include/python${PYTHON_VERSION}"
+fi
+AC_SUBST(PYTHON_INCLUDES)
+dnl check if the headers exist:
+save_CPPFLAGS="$CPPFLAGS"
+CPPFLAGS="$CPPFLAGS $PYTHON_INCLUDES"
+AC_TRY_CPP([#include <Python.h>],dnl
+[AC_MSG_RESULT(found)
+$1],dnl
+[AC_MSG_RESULT(not found)
+$2])
+CPPFLAGS="$save_CPPFLAGS"
+])