From 13b49d3374cca4eaffee5fa756192a234714c8ff Mon Sep 17 00:00:00 2001
From: Tim Peters <tim.peters@gmail.com>
Date: Sun, 23 Sep 2001 02:00:29 +0000
Subject: New function classify_class_attrs().  As a number of SF bug reports
 point out, pydoc doesn't tell you where class attributes were defined, gets
 several new 2.2 features wrong, and isn't aware of some new features checked
 in on Thursday <wink>.  pydoc is hampered in part because inspect.py has the
 same limitations.  Alas, I can't think of a way to fix this within the
 current architecture of inspect/pydoc:  it's simply not possible in 2.2 to
 figure out everything needed just from examining the object you get back from
 class.attr.  You also need the class context, and the method resolution
 order, and tests against various things that simply didn't exist before. 
 OTOH, knowledge of how to do that is getting quite complex, so doesn't belong
 in pydoc.

classify_class_attrs takes a different approach, analyzing all
the class attrs "at once", and returning the most interesting stuff for
each, all in one gulp.  pydoc needs to be reworked to use this for
classes (instead of the current "filter dir(class) umpteen times against
assorted predicates" approach).
---
 Lib/inspect.py           |  85 ++++++++++++++++++++
 Lib/test/test_inspect.py | 201 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 286 insertions(+)

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 3febf18..c5c6709 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -163,6 +163,91 @@ def getmembers(object, predicate=None):
     results.sort()
     return results
 
+def classify_class_attrs(cls):
+    """Return list of attribute-descriptor tuples.
+
+    For each name in dir(cls), the return list contains a 4-tuple
+    with these elements:
+
+        0. The name (a string).
+
+        1. The kind of attribute this is, one of these strings:
+               'class method'    created via classmethod()
+               'static method'   created via staticmethod()
+               'property'        created via property()
+               'method'          any other flavor of method
+               'data'            not a method
+
+        2. The class which defined this attribute (a class).
+
+        3. The object as obtained directly from the defining class's
+           __dict__, not via getattr.  This is especially important for
+           data attributes:  C.data is just a data object, but
+           C.__dict__['data'] may be a data descriptor with additional
+           info, like a __doc__ string.
+    """
+
+    mro = getmro(cls)
+    names = dir(cls)
+    result = []
+    for name in names:
+        # Get the object associated with the name.
+        # Getting an obj from the __dict__ sometimes reveals more than
+        # using getattr.  Static and class methods are dramatic examples.
+        if name in cls.__dict__:
+            obj = cls.__dict__[name]
+        else:
+            obj = getattr(cls, name)
+
+        # Figure out where it was defined.
+        # A complication:  static classes in 2.2 copy dict entries from
+        # bases into derived classes, so it's not enough just to look for
+        # "the first" class with the name in its dict.  OTOH:
+        # 1. Some-- but not all --methods in 2.2 come with an __objclass__
+        #    attr that answers the question directly.
+        # 2. Some-- but not all --classes in 2.2 have a __defined__ dict
+        #    saying which names were defined by the class.
+        homecls = getattr(obj, "__objclass__", None)
+        if homecls is None:
+            # Try __defined__.
+            for base in mro:
+                if hasattr(base, "__defined__"):
+                    if name in base.__defined__:
+                        homecls = base
+                        break
+        if homecls is None:
+            # Last chance (and first chance for classic classes):  search
+            # the dicts.
+            for base in mro:
+                if name in base.__dict__:
+                    homecls = base
+                    break
+
+        # Get the object again, in order to get it from the defining
+        # __dict__ instead of via getattr (if possible).
+        if homecls is not None and name in homecls.__dict__:
+            obj = homecls.__dict__[name]
+
+        # Also get the object via getattr.
+        obj_via_getattr = getattr(cls, name)
+
+        # Classify the object.
+        if isinstance(obj, staticmethod):
+            kind = "static method"
+        elif isinstance(obj, classmethod):
+            kind = "class method"
+        elif isinstance(obj, property):
+            kind = "property"
+        elif (ismethod(obj_via_getattr) or
+              ismethoddescriptor(obj_via_getattr)):
+            kind = "method"
+        else:
+            kind = "data"
+
+        result.append((name, kind, homecls, obj))
+
+    return result
+
 # ----------------------------------------------------------- class helpers
 def _searchbases(cls, accum):
     # Simulate the "classic class" search order.
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index dbb6609..9167b14 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -233,3 +233,204 @@ class D(B, C): pass
 expected = (D, B, C, A, object)
 got = inspect.getmro(D)
 test(expected == got, "expected %r mro, got %r", expected, got)
+
+# Test classify_class_attrs.
+def attrs_wo_objs(cls):
+    return [t[:3] for t in inspect.classify_class_attrs(cls)]
+
+class A:
+    def s(): pass
+    s = staticmethod(s)
+
+    def c(cls): pass
+    c = classmethod(c)
+
+    def getp(self): pass
+    p = property(getp)
+
+    def m(self): pass
+
+    def m1(self): pass
+
+    datablob = '1'
+
+attrs = attrs_wo_objs(A)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', A) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class B(A):
+    def m(self): pass
+
+attrs = attrs_wo_objs(B)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+
+class C(A):
+    def m(self): pass
+    def c(self): pass
+
+attrs = attrs_wo_objs(C)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'method', C) in attrs, 'missing plain method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', C) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class D(B, C):
+    def m1(self): pass
+
+attrs = attrs_wo_objs(D)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', D) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+# Repeat all that, but w/ new-style non-dynamic classes.
+
+class A(object):
+    __dynamic__ = 0
+
+    def s(): pass
+    s = staticmethod(s)
+
+    def c(cls): pass
+    c = classmethod(c)
+
+    def getp(self): pass
+    p = property(getp)
+
+    def m(self): pass
+
+    def m1(self): pass
+
+    datablob = '1'
+
+attrs = attrs_wo_objs(A)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', A) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class B(A):
+    __dynamic__ = 0
+
+    def m(self): pass
+
+attrs = attrs_wo_objs(B)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+
+class C(A):
+    __dynamic__ = 0
+
+    def m(self): pass
+    def c(self): pass
+
+attrs = attrs_wo_objs(C)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'method', C) in attrs, 'missing plain method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', C) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class D(B, C):
+    __dynamic__ = 0
+
+    def m1(self): pass
+
+attrs = attrs_wo_objs(D)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'method', C) in attrs, 'missing plain method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', D) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+# And again, but w/ new-style dynamic classes.
+
+class A(object):
+    __dynamic__ = 1
+
+    def s(): pass
+    s = staticmethod(s)
+
+    def c(cls): pass
+    c = classmethod(c)
+
+    def getp(self): pass
+    p = property(getp)
+
+    def m(self): pass
+
+    def m1(self): pass
+
+    datablob = '1'
+
+attrs = attrs_wo_objs(A)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', A) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class B(A):
+    __dynamic__ = 1
+
+    def m(self): pass
+
+attrs = attrs_wo_objs(B)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'class method', A) in attrs, 'missing class method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+
+class C(A):
+    __dynamic__ = 1
+
+    def m(self): pass
+    def c(self): pass
+
+attrs = attrs_wo_objs(C)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'method', C) in attrs, 'missing plain method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', C) in attrs, 'missing plain method')
+test(('m1', 'method', A) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
+
+class D(B, C):
+    __dynamic__ = 1
+
+    def m1(self): pass
+
+attrs = attrs_wo_objs(D)
+test(('s', 'static method', A) in attrs, 'missing static method')
+test(('c', 'method', C) in attrs, 'missing plain method')
+test(('p', 'property', A) in attrs, 'missing property')
+test(('m', 'method', B) in attrs, 'missing plain method')
+test(('m1', 'method', D) in attrs, 'missing plain method')
+test(('datablob', 'data', A) in attrs, 'missing data')
-- 
cgit v0.12

