Merge branch 'mromberg-implpkg'

* mromberg-implpkg:
  Minor edits to Python implicit namespace package docs
  use %inline for test
  use relative import for -builtin and python2
  Python3 removes support for relative imports
  Document implicit namespace packages for python
  disable namespace package build
  Attempt to calm the testing gods...
  use whatever name winders uses for .so files.
  Examples (and tests) for python namespace packages
  disable namespace package build
  spelling
  Attempt to calm the testing gods...
  use whatever name winders uses for .so files.
  Don't run example for old pythons
  Examples (and tests) for python namespace packages
  use importlib to load C extension modules for python 2.7 and newer

Examples/python/import_packages/README

@@ -1,2 +1,4 @@
 These are actually regression tests for SF bug #1297 (GH issue #7).
-See individual READMEs in subdirectories.
+The namespace_pkg is an example of python3's namespace packages.
+
+See individual READMEs in subdirectories.

Examples/python/import_packages/namespace_pkg/Makefile

@@ -0,0 +1,17 @@
+TOP        = ../../..
+SWIGEXE    = $(TOP)/../swig
+SWIG_LIB_DIR = $(TOP)/../$(TOP_BUILDDIR_TO_TOP_SRCDIR)Lib
+TARGET     = robin
+INTERFACE  = robin.i
+
+check: build
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' python_run
+
+build:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' SRCS='$(SRCS)' \
+	SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
+	TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' python
+
+clean:
+	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' TARGET='$(TARGET)' python_clean
+	rm -rf path1 path2 path3 path4.zip

Examples/python/import_packages/namespace_pkg/README

@@ -0,0 +1,25 @@
+  This is an example (and test) of using swig generated modules in the context
+of python3's namespace packages:
+
+https://www.python.org/dev/peps/pep-0420/
+
+  Consequently, this example requires python (3.3 or newer) to build and run.
+
+  This example creates a simple swig module named robin.  The robin.py module
+has a companion C module named _robin.so.  The robin module is tested in four
+ways:
+
+  1) As a non-package module (tested by nonpkg.py)
+
+  2) With robin.py and _robin.so in the brave package under the path1
+     subdirectory.  (tested by normal.py)
+
+  3) With robin.py in path2/brave and _robin.so in path3/brave
+     (tested by split.py)
+
+  4) With robin.py contained in a zip file (path4.zip) as brave/robin.py and
+     _robin.so found on the filesystem under path3/brave (tested by zipsplit.py)
+
+Note: Using namespace packages with subpackages (such as brave.sir.robin) where
+      robin.py is located in a zipfile requires python-3.5.1 or newer as
+      python's zipimporter only worked with packages of depth 1 until then.

Examples/python/import_packages/namespace_pkg/nonpkg.py

@@ -0,0 +1,5 @@
+# import robin as a module in the global namespace
+
+import robin
+
+assert(robin.run() == "AWAY!")

Examples/python/import_packages/namespace_pkg/normal.py

@@ -0,0 +1,7 @@
+import sys
+# Package brave found under one path
+sys.path.insert(0, 'path1')
+
+from brave import robin
+
+assert(robin.run() == "AWAY!")

Examples/python/import_packages/namespace_pkg/robin.i

@@ -0,0 +1,7 @@
+%module robin
+
+%inline %{
+const char *run(void) {
+    return "AWAY!";
+}
+%}

Examples/python/import_packages/namespace_pkg/runme.py

@@ -0,0 +1,51 @@
+# These examples rely on namespace packages.  Don't
+# run them for old python interpreters.
+import sys
+if sys.version_info < (3, 3, 0):
+    sys.exit(0)
+
+
+import os
+import shutil
+import zipfile
+
+
+def copyMods():
+    dirs = ['path1', 'path2', 'path3']
+
+    # Clean out any old package paths
+    for d in dirs:
+        if os.path.isdir(d):
+            shutil.rmtree(d)
+
+    for d in dirs:
+        os.mkdir(d)
+        os.mkdir(os.path.join(d, 'brave'))
+
+    shutil.copy('robin.py', os.path.join('path1', 'brave'))
+    os.system('cp _robin.* ' + os.path.join('path1', 'brave'))
+
+    shutil.copy('robin.py', os.path.join('path2', 'brave'))
+    os.system('cp _robin.* ' + os.path.join('path3', 'brave'))
+
+    mkzip()
+
+def mkzip():
+    zf = zipfile.ZipFile("path4.zip", "w")
+    zf.writestr("brave/", b'')
+    zf.write('robin.py', 'brave/robin.py')
+    zf.close()
+
+
+def main():
+    copyMods()
+
+    # Run each test with a separate interpreter
+    os.system(sys.executable + " nonpkg.py")
+    os.system(sys.executable + " normal.py")
+    os.system(sys.executable + " split.py")
+    os.system(sys.executable + " zipsplit.py")
+
+
+if __name__ == "__main__":
+    main()

Examples/python/import_packages/namespace_pkg/split.py

@@ -0,0 +1,9 @@
+import sys
+# Package brave split into two paths.
+# path2/brave/robin.py and path3/brave/_robin.so
+sys.path.insert(0, 'path2')
+sys.path.insert(0, 'path3')
+
+from brave import robin
+
+assert(robin.run() == "AWAY!")

Examples/python/import_packages/namespace_pkg/zipsplit.py

@@ -0,0 +1,9 @@
+import sys
+# Package brave split into two paths.
+# brave/robin.py (in path4.zip) and path3/brave/_robin.so
+sys.path.insert(0, 'path4.zip')
+sys.path.insert(0, 'path3')
+
+from brave import robin
+
+assert(robin.run() == "AWAY!")