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comparison planemo/lib/python3.7/site-packages/future/builtins/newsuper.py @ 0:d30785e31577 draft

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"planemo upload commit 6eee67778febed82ddd413c3ca40b3183a3898f1"
author guerler
date Fri, 31 Jul 2020 00:18:57 -0400
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1 '''
2 This module provides a newsuper() function in Python 2 that mimics the
3 behaviour of super() in Python 3. It is designed to be used as follows:
4
5 from __future__ import division, absolute_import, print_function
6 from future.builtins import super
7
8 And then, for example:
9
10 class VerboseList(list):
11 def append(self, item):
12 print('Adding an item')
13 super().append(item) # new simpler super() function
14
15 Importing this module on Python 3 has no effect.
16
17 This is based on (i.e. almost identical to) Ryan Kelly's magicsuper
18 module here:
19
20 https://github.com/rfk/magicsuper.git
21
22 Excerpts from Ryan's docstring:
23
24 "Of course, you can still explicitly pass in the arguments if you want
25 to do something strange. Sometimes you really do want that, e.g. to
26 skip over some classes in the method resolution order.
27
28 "How does it work? By inspecting the calling frame to determine the
29 function object being executed and the object on which it's being
30 called, and then walking the object's __mro__ chain to find out where
31 that function was defined. Yuck, but it seems to work..."
32 '''
33
34 from __future__ import absolute_import
35 import sys
36 from types import FunctionType
37
38 from future.utils import PY3, PY26
39
40
41 _builtin_super = super
42
43 _SENTINEL = object()
44
45 def newsuper(typ=_SENTINEL, type_or_obj=_SENTINEL, framedepth=1):
46 '''Like builtin super(), but capable of magic.
47
48 This acts just like the builtin super() function, but if called
49 without any arguments it attempts to infer them at runtime.
50 '''
51 # Infer the correct call if used without arguments.
52 if typ is _SENTINEL:
53 # We'll need to do some frame hacking.
54 f = sys._getframe(framedepth)
55
56 try:
57 # Get the function's first positional argument.
58 type_or_obj = f.f_locals[f.f_code.co_varnames[0]]
59 except (IndexError, KeyError,):
60 raise RuntimeError('super() used in a function with no args')
61
62 try:
63 # Get the MRO so we can crawl it.
64 mro = type_or_obj.__mro__
65 except (AttributeError, RuntimeError): # see issue #160
66 try:
67 mro = type_or_obj.__class__.__mro__
68 except AttributeError:
69 raise RuntimeError('super() used with a non-newstyle class')
70
71 # A ``for...else`` block? Yes! It's odd, but useful.
72 # If unfamiliar with for...else, see:
73 #
74 # http://psung.blogspot.com/2007/12/for-else-in-python.html
75 for typ in mro:
76 # Find the class that owns the currently-executing method.
77 for meth in typ.__dict__.values():
78 # Drill down through any wrappers to the underlying func.
79 # This handles e.g. classmethod() and staticmethod().
80 try:
81 while not isinstance(meth,FunctionType):
82 if isinstance(meth, property):
83 # Calling __get__ on the property will invoke
84 # user code which might throw exceptions or have
85 # side effects
86 meth = meth.fget
87 else:
88 try:
89 meth = meth.__func__
90 except AttributeError:
91 meth = meth.__get__(type_or_obj, typ)
92 except (AttributeError, TypeError):
93 continue
94 if meth.func_code is f.f_code:
95 break # Aha! Found you.
96 else:
97 continue # Not found! Move onto the next class in MRO.
98 break # Found! Break out of the search loop.
99 else:
100 raise RuntimeError('super() called outside a method')
101
102 # Dispatch to builtin super().
103 if type_or_obj is not _SENTINEL:
104 return _builtin_super(typ, type_or_obj)
105 return _builtin_super(typ)
106
107
108 def superm(*args, **kwds):
109 f = sys._getframe(1)
110 nm = f.f_code.co_name
111 return getattr(newsuper(framedepth=2),nm)(*args, **kwds)
112
113
114 __all__ = ['newsuper']