Move knee.py from Lib/ to Demo/imputil/. Fixes #515745.

1 files changed, 126 insertions, 0 deletions

diff --git a/Demo/imputil/knee.py b/Demo/imputil/knee.py
new file mode 100644
index 0000000..64764da
--- /dev/null
+++ b/Demo/imputil/knee.py
@@ -0,0 +1,126 @@
+"""An Python re-implementation of hierarchical module import.
+
+This code is intended to be read, not executed.  However, it does work
+-- all you need to do to enable it is "import knee".
+
+(The name is a pun on the klunkier predecessor of this module, "ni".)
+
+"""
+
+import sys, imp, __builtin__
+
+
+# Replacement for __import__()
+def import_hook(name, globals=None, locals=None, fromlist=None):
+    parent = determine_parent(globals)
+    q, tail = find_head_package(parent, name)
+    m = load_tail(q, tail)
+    if not fromlist:
+        return q
+    if hasattr(m, "__path__"):
+        ensure_fromlist(m, fromlist)
+    return m
+
+def determine_parent(globals):
+    if not globals or  not globals.has_key("__name__"):
+        return None
+    pname = globals['__name__']
+    if globals.has_key("__path__"):
+        parent = sys.modules[pname]
+        assert globals is parent.__dict__
+        return parent
+    if '.' in pname:
+        i = pname.rfind('.')
+        pname = pname[:i]
+        parent = sys.modules[pname]
+        assert parent.__name__ == pname
+        return parent
+    return None
+
+def find_head_package(parent, name):
+    if '.' in name:
+        i = name.find('.')
+        head = name[:i]
+        tail = name[i+1:]
+    else:
+        head = name
+        tail = ""
+    if parent:
+        qname = "%s.%s" % (parent.__name__, head)
+    else:
+        qname = head
+    q = import_module(head, qname, parent)
+    if q: return q, tail
+    if parent:
+        qname = head
+        parent = None
+        q = import_module(head, qname, parent)
+        if q: return q, tail
+    raise ImportError, "No module named " + qname
+
+def load_tail(q, tail):
+    m = q
+    while tail:
+        i = tail.find('.')
+        if i < 0: i = len(tail)
+        head, tail = tail[:i], tail[i+1:]
+        mname = "%s.%s" % (m.__name__, head)
+        m = import_module(head, mname, m)
+        if not m:
+            raise ImportError, "No module named " + mname
+    return m
+
+def ensure_fromlist(m, fromlist, recursive=0):
+    for sub in fromlist:
+        if sub == "*":
+            if not recursive:
+                try:
+                    all = m.__all__
+                except AttributeError:
+                    pass
+                else:
+                    ensure_fromlist(m, all, 1)
+            continue
+        if sub != "*" and not hasattr(m, sub):
+            subname = "%s.%s" % (m.__name__, sub)
+            submod = import_module(sub, subname, m)
+            if not submod:
+                raise ImportError, "No module named " + subname
+
+def import_module(partname, fqname, parent):
+    try:
+        return sys.modules[fqname]
+    except KeyError:
+        pass
+    try:
+        fp, pathname, stuff = imp.find_module(partname,
+                                              parent and parent.__path__)
+    except ImportError:
+        return None
+    try:
+        m = imp.load_module(fqname, fp, pathname, stuff)
+    finally:
+        if fp: fp.close()
+    if parent:
+        setattr(parent, partname, m)
+    return m
+
+
+# Replacement for reload()
+def reload_hook(module):
+    name = module.__name__
+    if '.' not in name:
+        return import_module(name, name, None)
+    i = name.rfind('.')
+    pname = name[:i]
+    parent = sys.modules[pname]
+    return import_module(name[i+1:], name, parent)
+
+
+# Save the original hooks
+original_import = __builtin__.__import__
+original_reload = __builtin__.reload
+
+# Now install our hooks
+__builtin__.__import__ = import_hook
+__builtin__.reload = reload_hook