importlib: Add reimplemented basic importlib module.

Signed-off-by: Andrew Leech <andrew@alelec.net>

Author: pi-anl

python-stdlib/importlib/importlib.py

@@ -0,0 +1,36 @@
+"""
+Provide subset of CPython api-compatible importlib module.
+"""
+import sys
+
+
+def import_module(name, package=None):
+    # https://docs.python.org/3/library/importlib.html#importlib.import_module
+    if package:
+        raise NotImplementedError()
+    mods = name.split(".")
+    mod = __import__(name)
+    while len(mods) > 1:
+        mod = getattr(mod, mods.pop(1))
+    return mod
+
+
+def reload(module):
+    """
+    https://docs.python.org/3/library/importlib.html#importlib.reload
+    """
+    fullname = module.__name__
+    if sys.modules.get(fullname) is not module:
+        raise ImportError("module %s not in sys.modules" % fullname)
+    sys.modules.pop(fullname)
+    newmod = import_module(fullname)
+    try:
+        # Update parent frame object
+        pfglobals = sys._getframe(1).f_globals
+        for name, obj in list(pfglobals.items()):
+            if obj is module:
+                pfglobals[name] = newmod
+    except AttributeError:
+        # Can't update parent frame without sys._getframe
+        pass
+    return newmod

python-stdlib/importlib/manifest.py

@@ -0,0 +1,3 @@
+metadata(version="0.1.0")
+
+module("importlib.py")

python-stdlib/importlib/tests/imp1/importlib_test_data.py

@@ -0,0 +1 @@
+test_data = "one"

python-stdlib/importlib/tests/imp2/importlib_test_data.py

@@ -0,0 +1 @@
+test_data = "two"

python-stdlib/importlib/tests/test_importlib.py

@@ -0,0 +1,15 @@
+import sys
+sys.path.append(".")
+import importlib
+
+sys.path.append("tests/imp1")
+import importlib_test_data
+assert importlib_test_data.test_data == "one"
+
+sys.path.remove("tests/imp1")
+sys.path.append("tests/imp2")
+
+nm = importlib.reload(importlib_test_data)
+import importlib_test_data
+
+assert importlib_test_data.test_data == "two"