PEP 302 + zipimport:

- new import hooks in import.c, exposed in the sys module
- new module called 'zipimport'
- various changes to allow bootstrapping from zip files

I hope I didn't break the Windows build (or anything else for that
matter), but then again, it's been sitting on sf long enough...

Regarding the latest discussions on python-dev: zipimport sets
pkg.__path__ as specified in PEP 273, and likewise, sys.path item such as
/path/to/Archive.zip/subdir/ are supported again.

Lib/test/test_zipimport.py

@@ -0,0 +1,180 @@
+import sys
+import os
+import marshal
+import imp
+import struct
+import time
+
+import zlib # implied prerequisite
+from zipfile import ZipFile, ZipInfo, ZIP_STORED, ZIP_DEFLATED
+from test import test_support
+from test.test_importhooks import ImportHooksBaseTestCase, test_src, test_co
+
+import zipimport
+
+
+def make_pyc(co, mtime):
+    data = marshal.dumps(co)
+    pyc = imp.get_magic() + struct.pack("<i", mtime) + data
+    return pyc
+
+NOW = time.time()
+test_pyc = make_pyc(test_co, NOW)
+
+
+if __debug__:
+    pyc_ext = ".pyc"
+else:
+    pyc_ext = ".pyo"
+
+
+TESTMOD = "ziptestmodule"
+TESTPACK = "ziptestpackage"
+TEMP_ZIP = "junk95142.zip"
+
+
+class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
+
+    compression = ZIP_STORED
+
+    def setUp(self):
+        # We're reusing the zip archive path, so we must clear the
+        # cached directory info.
+        zipimport._zip_directory_cache.clear()
+        ImportHooksBaseTestCase.setUp(self)
+
+    def doTest(self, expected_ext, files, *modules):
+        z = ZipFile(TEMP_ZIP, "w")
+        try:
+            for name, (mtime, data) in files.items():
+                zinfo = ZipInfo(name, time.localtime(mtime))
+                zinfo.compress_type = self.compression
+                z.writestr(zinfo, data)
+            z.close()
+            sys.path.insert(0, TEMP_ZIP)
+
+            mod = __import__(".".join(modules), globals(), locals(),
+                             ["__dummy__"])
+            file = mod.get_file()
+            self.assertEquals(file, os.path.join(TEMP_ZIP,
+                              os.sep.join(modules) + expected_ext))
+        finally:
+            z.close()
+            os.remove(TEMP_ZIP)
+
+    def testAFakeZlib(self):
+        #
+        # This could cause a stack overflow before: importing zlib.py
+        # from a compressed archive would cause zlib to be imported
+        # which would find zlib.py in the archive, which would... etc.
+        #
+        # This test *must* be executed first: it must be the first one
+        # to trigger zipimport to import zlib (zipimport caches the
+        # zlib.decompress function object, after which the problem being
+        # tested here wouldn't be a problem anymore...
+        # (Hence the 'A' in the test method name: to make it the first
+        # item in a list sorted by name, like unittest.makeSuite() does.)
+        #
+        if "zlib" in sys.modules:
+            del sys.modules["zlib"]
+        files = {"zlib.py": (NOW, test_src)}
+        try:
+            self.doTest(".py", files, "zlib")
+        except ImportError:
+            if self.compression != ZIP_DEFLATED:
+                self.fail("expected test to not raise ImportError")
+        else:
+            if self.compression != ZIP_STORED:
+                self.fail("expected test to raise ImportError")
+
+    def testPy(self):
+        files = {TESTMOD + ".py": (NOW, test_src)}
+        self.doTest(".py", files, TESTMOD)
+
+    def testPyc(self):
+        files = {TESTMOD + pyc_ext: (NOW, test_pyc)}
+        self.doTest(pyc_ext, files, TESTMOD)
+
+    def testBoth(self):
+        files = {TESTMOD + ".py": (NOW, test_src),
+                 TESTMOD + pyc_ext: (NOW, test_pyc)}
+        self.doTest(pyc_ext, files, TESTMOD)
+
+    def testBadMagic(self):
+        # make pyc magic word invalid, forcing loading from .py
+        m0 = ord(test_pyc[0])
+        m0 ^= 0x04  # flip an arbitrary bit
+        badmagic_pyc = chr(m0) + test_pyc[1:]
+        files = {TESTMOD + ".py": (NOW, test_src),
+                 TESTMOD + pyc_ext: (NOW, badmagic_pyc)}
+        self.doTest(".py", files, TESTMOD)
+
+    def testBadMagic2(self):
+        # make pyc magic word invalid, causing an ImportError
+        m0 = ord(test_pyc[0])
+        m0 ^= 0x04  # flip an arbitrary bit
+        badmagic_pyc = chr(m0) + test_pyc[1:]
+        files = {TESTMOD + pyc_ext: (NOW, badmagic_pyc)}
+        try:
+            self.doTest(".py", files, TESTMOD)
+        except ImportError:
+            pass
+        else:
+            self.fail("expected ImportError; import from bad pyc")
+
+    def testBadMTime(self):
+        t3 = ord(test_pyc[7])
+        t3 ^= 0x02  # flip the second bit -- not the first as that one
+                    # isn't stored in the .py's mtime in the zip archive.
+        badtime_pyc = test_pyc[:7] + chr(t3) + test_pyc[8:]
+        files = {TESTMOD + ".py": (NOW, test_src),
+                 TESTMOD + pyc_ext: (NOW, badtime_pyc)}
+        self.doTest(".py", files, TESTMOD)
+
+    def testPackage(self):
+        packdir = TESTPACK + os.sep
+        files = {packdir + "__init__" + pyc_ext: (NOW, test_pyc),
+                 packdir + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        self.doTest(pyc_ext, files, TESTPACK, TESTMOD)
+
+    def testDeepPackage(self):
+        packdir = TESTPACK + os.sep
+        packdir2 = packdir + packdir
+        files = {packdir + "__init__" + pyc_ext: (NOW, test_pyc),
+                 packdir2 + "__init__" + pyc_ext: (NOW, test_pyc),
+                 packdir2 + TESTMOD + pyc_ext: (NOW, test_pyc)}
+        self.doTest(pyc_ext, files, TESTPACK, TESTPACK, TESTMOD)
+
+    def testGetData(self):
+        z = ZipFile(TEMP_ZIP, "w")
+        z.compression = self.compression
+        try:
+            name = "testdata.dat"
+            data = "".join([chr(x) for x in range(256)]) * 500
+            z.writestr(name, data)
+            z.close()
+            zi = zipimport.zipimporter(TEMP_ZIP)
+            self.assertEquals(data, zi.get_data(name))
+        finally:
+            z.close()
+            os.remove(TEMP_ZIP)
+
+    def testImporterAttr(self):
+        src = """if 1:  # indent hack
+        def get_file():
+            return __file__
+        if __importer__.get_data("some.data") != "some data":
+            raise AssertionError, "bad data"\n"""
+        pyc = make_pyc(compile(src, "<???>", "exec"), NOW)
+        files = {TESTMOD + pyc_ext: (NOW, pyc),
+                 "some.data": (NOW, "some data")}
+        self.doTest(pyc_ext, files, TESTMOD)
+
+
+class CompressedZipImportTestCase(UncompressedZipImportTestCase):
+    compression = ZIP_DEFLATED
+
+
+if __name__ == "__main__":
+    test_support.run_unittest(UncompressedZipImportTestCase)
+    test_support.run_unittest(CompressedZipImportTestCase)