Issue #17633: Improve support for namespace packages with zipimport.

Previously zipimport mistakenly limited namespace support to only the
top-level of the zipfile when it should have supported an arbitrary
depth.

Thanks to Phil Connel for the bug report and initial patch and Mike
Romberg for the final patch.

Lib/test/test_zipimport.py

 import sys
 import os
 import marshal
+import importlib
 import importlib.util
 import struct
 import time
@@ -48,6 +49,7 @@ test_pyc = make_pyc(test_co, NOW, len(test_src))
 TESTMOD = "ziptestmodule"
 TESTPACK = "ziptestpackage"
 TESTPACK2 = "ziptestpackage2"
+TEMP_DIR = os.path.abspath("junk95142")
 TEMP_ZIP = os.path.abspath("junk95142.zip")
 
 pyc_file = importlib.util.cache_from_source(TESTMOD + '.py')
@@ -77,33 +79,55 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
 
     def setUp(self):
         # We're reusing the zip archive path, so we must clear the
-        # cached directory info and linecache
+        # cached directory info and linecache.
         linecache.clearcache()
         zipimport._zip_directory_cache.clear()
         ImportHooksBaseTestCase.setUp(self)
 
-    def doTest(self, expected_ext, files, *modules, **kw):
-        z = ZipFile(TEMP_ZIP, "w")
-        try:
+    def makeTree(self, files, dirName=TEMP_DIR):
+        # Create a filesystem based set of modules/packages
+        # defined by files under the directory dirName.
+        self.addCleanup(support.rmtree, dirName)
+
+        for name, (mtime, data) in files.items():
+            path = os.path.join(dirName, name)
+            if path[-1] == os.sep:
+                if not os.path.isdir(path):
+                    os.makedirs(path)
+            else:
+                dname = os.path.dirname(path)
+                if not os.path.isdir(dname):
+                    os.makedirs(dname)
+                with open(path, 'wb') as fp:
+                    fp.write(data)
+
+    def makeZip(self, files, zipName=TEMP_ZIP, **kw):
+        # Create a zip archive based set of modules/packages
+        # defined by files in the zip file zipName.  If the
+        # key 'stuff' exists in kw it is prepended to the archive.
+        self.addCleanup(support.unlink, zipName)
+
+        with ZipFile(zipName, "w") as z:
             for name, (mtime, data) in files.items():
                 zinfo = ZipInfo(name, time.localtime(mtime))
                 zinfo.compress_type = self.compression
                 z.writestr(zinfo, data)
-            z.close()
 
         stuff = kw.get("stuff", None)
         if stuff is not None:
             # Prepend 'stuff' to the start of the zipfile
-                with open(TEMP_ZIP, "rb") as f:
+            with open(zipName, "rb") as f:
                 data = f.read()
-                with open(TEMP_ZIP, "wb") as f:
+            with open(zipName, "wb") as f:
                 f.write(stuff)
                 f.write(data)
 
+    def doTest(self, expected_ext, files, *modules, **kw):
+        self.makeZip(files, **kw)
+
         sys.path.insert(0, TEMP_ZIP)
 
-            mod = __import__(".".join(modules), globals(), locals(),
-                             ["__dummy__"])
+        mod = importlib.import_module(".".join(modules))
 
         call = kw.get('call')
         if call is not None:
@@ -113,9 +137,6 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
             file = mod.get_file()
             self.assertEqual(file, os.path.join(TEMP_ZIP,
                                  *modules) + expected_ext)
-        finally:
-            z.close()
-            os.remove(TEMP_ZIP)
 
     def testAFakeZlib(self):
         #
@@ -201,7 +222,9 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
                  packdir + TESTMOD + pyc_ext: (NOW, test_pyc)}
         self.doTest(pyc_ext, files, TESTPACK, TESTMOD)
 
-    def testDeepPackage(self):
+    def testSubPackage(self):
+        # Test that subpackages function when loaded from zip
+        # archives.
         packdir = TESTPACK + os.sep
         packdir2 = packdir + TESTPACK2 + os.sep
         files = {packdir + "__init__" + pyc_ext: (NOW, test_pyc),
@@ -209,6 +232,167 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
                  packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
         self.doTest(pyc_ext, files, TESTPACK, TESTPACK2, TESTMOD)
 
+    def testSubNamespacePackage(self):
+        # Test that implicit namespace subpackages function
+        # when loaded from zip archives.
+        packdir = TESTPACK + os.sep
+        packdir2 = packdir + TESTPACK2 + os.sep
+        # The first two files are just directory entries (so have no data).
+        files = {packdir: (NOW, ""),
+                 packdir2: (NOW, ""),
+                 packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        self.doTest(pyc_ext, files, TESTPACK, TESTPACK2, TESTMOD)
+
+    def testMixedNamespacePackage(self):
+        # Test implicit namespace packages spread between a
+        # real filesystem and a zip archive.
+        packdir = TESTPACK + os.sep
+        packdir2 = packdir + TESTPACK2 + os.sep
+        packdir3 = packdir2 + TESTPACK + '3' + os.sep
+        files1 = {packdir: (NOW, ""),
+                  packdir + TESTMOD + pyc_ext: (NOW, test_pyc),
+                  packdir2: (NOW, ""),
+                  packdir3: (NOW, ""),
+                  packdir3 + TESTMOD + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + '3' + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        files2 = {packdir: (NOW, ""),
+                  packdir + TESTMOD + '2' + pyc_ext: (NOW, test_pyc),
+                  packdir2: (NOW, ""),
+                  packdir2 + TESTMOD + '2' + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+
+        zip1 = os.path.abspath("path1.zip")
+        self.makeZip(files1, zip1)
+
+        zip2 = TEMP_DIR
+        self.makeTree(files2, zip2)
+
+        # zip2 should override zip1.
+        sys.path.insert(0, zip1)
+        sys.path.insert(0, zip2)
+
+        mod = importlib.import_module(TESTPACK)
+
+        # if TESTPACK is functioning as a namespace pkg then
+        # there should be two entries in the __path__.
+        # First should be path2 and second path1.
+        self.assertEqual(2, len(mod.__path__))
+        p1, p2 = mod.__path__
+        self.assertEqual(os.path.basename(TEMP_DIR), p1.split(os.sep)[-2])
+        self.assertEqual("path1.zip", p2.split(os.sep)[-2])
+
+        # packdir3 should import as a namespace package.
+        # Its __path__ is an iterable of 1 element from zip1.
+        mod = importlib.import_module(packdir3.replace(os.sep, '.')[:-1])
+        self.assertEqual(1, len(mod.__path__))
+        mpath = list(mod.__path__)[0].split('path1.zip' + os.sep)[1]
+        self.assertEqual(packdir3[:-1], mpath)
+
+        # TESTPACK/TESTMOD only exists in path1.
+        mod = importlib.import_module('.'.join((TESTPACK, TESTMOD)))
+        self.assertEqual("path1.zip", mod.__file__.split(os.sep)[-3])
+
+        # And TESTPACK/(TESTMOD + '2') only exists in path2.
+        mod = importlib.import_module('.'.join((TESTPACK, TESTMOD + '2')))
+        self.assertEqual(os.path.basename(TEMP_DIR),
+                         mod.__file__.split(os.sep)[-3])
+
+        # One level deeper...
+        subpkg = '.'.join((TESTPACK, TESTPACK2))
+        mod = importlib.import_module(subpkg)
+        self.assertEqual(2, len(mod.__path__))
+        p1, p2 = mod.__path__
+        self.assertEqual(os.path.basename(TEMP_DIR), p1.split(os.sep)[-3])
+        self.assertEqual("path1.zip", p2.split(os.sep)[-3])
+
+        # subpkg.TESTMOD exists in both zips should load from zip2.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD)))
+        self.assertEqual(os.path.basename(TEMP_DIR),
+                         mod.__file__.split(os.sep)[-4])
+
+        # subpkg.TESTMOD + '2' only exists in zip2.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD + '2')))
+        self.assertEqual(os.path.basename(TEMP_DIR),
+                         mod.__file__.split(os.sep)[-4])
+
+        # Finally subpkg.TESTMOD + '3' only exists in zip1.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD + '3')))
+        self.assertEqual('path1.zip', mod.__file__.split(os.sep)[-4])
+
+    def testNamespacePackage(self):
+        # Test implicit namespace packages spread between multiple zip
+        # archives.
+        packdir = TESTPACK + os.sep
+        packdir2 = packdir + TESTPACK2 + os.sep
+        packdir3 = packdir2 + TESTPACK + '3' + os.sep
+        files1 = {packdir: (NOW, ""),
+                  packdir + TESTMOD + pyc_ext: (NOW, test_pyc),
+                  packdir2: (NOW, ""),
+                  packdir3: (NOW, ""),
+                  packdir3 + TESTMOD + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + '3' + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        zip1 = os.path.abspath("path1.zip")
+        self.makeZip(files1, zip1)
+
+        files2 = {packdir: (NOW, ""),
+                  packdir + TESTMOD + '2' + pyc_ext: (NOW, test_pyc),
+                  packdir2: (NOW, ""),
+                  packdir2 + TESTMOD + '2' + pyc_ext: (NOW, test_pyc),
+                  packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        zip2 = os.path.abspath("path2.zip")
+        self.makeZip(files2, zip2)
+
+        # zip2 should override zip1.
+        sys.path.insert(0, zip1)
+        sys.path.insert(0, zip2)
+
+        mod = importlib.import_module(TESTPACK)
+
+        # if TESTPACK is functioning as a namespace pkg then
+        # there should be two entries in the __path__.
+        # First should be path2 and second path1.
+        self.assertEqual(2, len(mod.__path__))
+        p1, p2 = mod.__path__
+        self.assertEqual("path2.zip", p1.split(os.sep)[-2])
+        self.assertEqual("path1.zip", p2.split(os.sep)[-2])
+
+        # packdir3 should import as a namespace package.
+        # Tts __path__ is an iterable of 1 element from zip1.
+        mod = importlib.import_module(packdir3.replace(os.sep, '.')[:-1])
+        self.assertEqual(1, len(mod.__path__))
+        mpath = list(mod.__path__)[0].split('path1.zip' + os.sep)[1]
+        self.assertEqual(packdir3[:-1], mpath)
+
+        # TESTPACK/TESTMOD only exists in path1.
+        mod = importlib.import_module('.'.join((TESTPACK, TESTMOD)))
+        self.assertEqual("path1.zip", mod.__file__.split(os.sep)[-3])
+
+        # And TESTPACK/(TESTMOD + '2') only exists in path2.
+        mod = importlib.import_module('.'.join((TESTPACK, TESTMOD + '2')))
+        self.assertEqual("path2.zip", mod.__file__.split(os.sep)[-3])
+
+        # One level deeper...
+        subpkg = '.'.join((TESTPACK, TESTPACK2))
+        mod = importlib.import_module(subpkg)
+        self.assertEqual(2, len(mod.__path__))
+        p1, p2 = mod.__path__
+        self.assertEqual("path2.zip", p1.split(os.sep)[-3])
+        self.assertEqual("path1.zip", p2.split(os.sep)[-3])
+
+        # subpkg.TESTMOD exists in both zips should load from zip2.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD)))
+        self.assertEqual('path2.zip', mod.__file__.split(os.sep)[-4])
+
+        # subpkg.TESTMOD + '2' only exists in zip2.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD + '2')))
+        self.assertEqual('path2.zip', mod.__file__.split(os.sep)[-4])
+
+        # Finally subpkg.TESTMOD + '3' only exists in zip1.
+        mod = importlib.import_module('.'.join((subpkg, TESTMOD + '3')))
+        self.assertEqual('path1.zip', mod.__file__.split(os.sep)[-4])
+
     def testZipImporterMethods(self):
         packdir = TESTPACK + os.sep
         packdir2 = packdir + TESTPACK2 + os.sep
@@ -231,7 +415,7 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
             mod = zi.load_module(TESTPACK)
             self.assertEqual(zi.get_filename(TESTPACK), mod.__file__)
 
-            existing_pack_path = __import__(TESTPACK).__path__[0]
+            existing_pack_path = importlib.import_module(TESTPACK).__path__[0]
             expected_path_path = os.path.join(TEMP_ZIP, TESTPACK)
             self.assertEqual(existing_pack_path, expected_path_path)
 
@@ -241,8 +425,8 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
 
             mod_path = packdir2 + TESTMOD
             mod_name = module_path_to_dotted_name(mod_path)
-            __import__(mod_name)
-            mod = sys.modules[mod_name]
+            mod = importlib.import_module(mod_name)
+            self.assertTrue(mod_name in sys.modules)
             self.assertEqual(zi.get_source(TESTPACK), None)
             self.assertEqual(zi.get_source(mod_path), None)
             self.assertEqual(zi.get_filename(mod_path), mod.__file__)
@@ -289,13 +473,13 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
 
             mod_path = TESTPACK2 + os.sep + TESTMOD
             mod_name = module_path_to_dotted_name(mod_path)
-            __import__(mod_name)
-            mod = sys.modules[mod_name]
+            mod = importlib.import_module(mod_name)
+            self.assertTrue(mod_name in sys.modules)
             self.assertEqual(zi.get_source(TESTPACK2), None)
             self.assertEqual(zi.get_source(mod_path), None)
             self.assertEqual(zi.get_filename(mod_path), mod.__file__)
             # To pass in the module name instead of the path, we must use the
-            # right importer
+            # right importer.
             loader = mod.__loader__
             self.assertEqual(loader.get_source(mod_name), None)
             self.assertEqual(loader.get_filename(mod_name), mod.__file__)

Misc/NEWS

@@ -44,6 +44,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #17633: Improve zipimport's support for namespace packages.
+
 - Issue #24705: Fix sysconfig._parse_makefile not expanding ${} vars
   appearing before $() vars.
 

Modules/zipimport.c

@@ -324,17 +324,14 @@ get_module_info(ZipImporter *self, PyObject *fullname)
 }
 
 typedef enum {
-    FL_ERROR,
-    FL_NOT_FOUND,
-    FL_MODULE_FOUND,
-    FL_NS_FOUND
+    FL_ERROR = -1,       /* error */
+    FL_NOT_FOUND,        /* no loader or namespace portions found */
+    FL_MODULE_FOUND,     /* module/package found */
+    FL_NS_FOUND          /* namespace portion found: */
+                         /* *namespace_portion will point to the name */
 } find_loader_result;
 
-/* The guts of "find_loader" and "find_module". Return values:
-   -1: error
-    0: no loader or namespace portions found
-    1: module/package found
-    2: namespace portion found: *namespace_portion will point to the name
+/* The guts of "find_loader" and "find_module".
 */
 static find_loader_result
 find_loader(ZipImporter *self, PyObject *fullname, PyObject **namespace_portion)
@@ -349,21 +346,34 @@ find_loader(ZipImporter *self, PyObject *fullname, PyObject **namespace_portion)
     if (mi == MI_NOT_FOUND) {
         /* Not a module or regular package. See if this is a directory, and
            therefore possibly a portion of a namespace package. */
-        int is_dir = check_is_directory(self, self->prefix, fullname);
+        find_loader_result result = FL_NOT_FOUND;
+        PyObject *subname;
+        int is_dir;
+
+        /* We're only interested in the last path component of fullname;
+           earlier components are recorded in self->prefix. */
+        subname = get_subname(fullname);
+        if (subname == NULL) {
+            return FL_ERROR;
+        }
+
+        is_dir = check_is_directory(self, self->prefix, subname);
         if (is_dir < 0)
-            return -1;
-        if (is_dir) {
+            result = FL_ERROR;
+        else if (is_dir) {
             /* This is possibly a portion of a namespace
                package. Return the string representing its path,
                without a trailing separator. */
             *namespace_portion = PyUnicode_FromFormat("%U%c%U%U",
                                                       self->archive, SEP,
-                                                      self->prefix, fullname);
+                                                      self->prefix, subname);
             if (*namespace_portion == NULL)
-                return FL_ERROR;
-            return FL_NS_FOUND;
+                result = FL_ERROR;
+            else
+                result = FL_NS_FOUND;
         }
-        return FL_NOT_FOUND;
+        Py_DECREF(subname);
+        return result;
     }
     /* This is a module or package. */
     return FL_MODULE_FOUND;
@@ -397,6 +407,9 @@ zipimporter_find_module(PyObject *obj, PyObject *args)
     case FL_MODULE_FOUND:
         result = (PyObject *)self;
         break;
+    default:
+        PyErr_BadInternalCall();
+        return NULL;
     }
     Py_INCREF(result);
     return result;
@@ -433,6 +446,9 @@ zipimporter_find_loader(PyObject *obj, PyObject *args)
         result = Py_BuildValue("O[O]", Py_None, namespace_portion);
         Py_DECREF(namespace_portion);
         return result;
+    default:
+        PyErr_BadInternalCall();
+        return NULL;
     }
     return result;
 }