Отредактировано, чтобы проверить, повлияет ли внешнее состояние на функцию сортировки, а также эквивалентны ли эти две функции.
Я взломал dis.dis и друзей для вывода в глобальный файлоподобный объект,Затем я вычеркнул номера строк и нормализованные имена переменных (не касаясь констант) и сравнил результат.
Вы можете убрать это, чтобы dis.dis и друзья yield исключили строки, чтобы вам не пришлосьзаманить их в ловушку.Но это рабочее подтверждение концепции использования dis.dis для сравнения функций с минимальными изменениями.
import types
from opcode import *
_have_code = (types.MethodType, types.FunctionType, types.CodeType,
types.ClassType, type)
def dis(x):
"""Disassemble classes, methods, functions, or code.
With no argument, disassemble the last traceback.
"""
if isinstance(x, types.InstanceType):
x = x.__class__
if hasattr(x, 'im_func'):
x = x.im_func
if hasattr(x, 'func_code'):
x = x.func_code
if hasattr(x, '__dict__'):
items = x.__dict__.items()
items.sort()
for name, x1 in items:
if isinstance(x1, _have_code):
print >> out, "Disassembly of %s:" % name
try:
dis(x1)
except TypeError, msg:
print >> out, "Sorry:", msg
print >> out
elif hasattr(x, 'co_code'):
disassemble(x)
elif isinstance(x, str):
disassemble_string(x)
else:
raise TypeError, \
"don't know how to disassemble %s objects" % \
type(x).__name__
def disassemble(co, lasti=-1):
"""Disassemble a code object."""
code = co.co_code
labels = findlabels(code)
linestarts = dict(findlinestarts(co))
n = len(code)
i = 0
extended_arg = 0
free = None
while i < n:
c = code[i]
op = ord(c)
if i in linestarts:
if i > 0:
print >> out
print >> out, "%3d" % linestarts[i],
else:
print >> out, ' ',
if i == lasti: print >> out, '-->',
else: print >> out, ' ',
if i in labels: print >> out, '>>',
else: print >> out, ' ',
print >> out, repr(i).rjust(4),
print >> out, opname[op].ljust(20),
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256 + extended_arg
extended_arg = 0
i = i+2
if op == EXTENDED_ARG:
extended_arg = oparg*65536L
print >> out, repr(oparg).rjust(5),
if op in hasconst:
print >> out, '(' + repr(co.co_consts[oparg]) + ')',
elif op in hasname:
print >> out, '(' + co.co_names[oparg] + ')',
elif op in hasjrel:
print >> out, '(to ' + repr(i + oparg) + ')',
elif op in haslocal:
print >> out, '(' + co.co_varnames[oparg] + ')',
elif op in hascompare:
print >> out, '(' + cmp_op[oparg] + ')',
elif op in hasfree:
if free is None:
free = co.co_cellvars + co.co_freevars
print >> out, '(' + free[oparg] + ')',
print >> out
def disassemble_string(code, lasti=-1, varnames=None, names=None,
constants=None):
labels = findlabels(code)
n = len(code)
i = 0
while i < n:
c = code[i]
op = ord(c)
if i == lasti: print >> out, '-->',
else: print >> out, ' ',
if i in labels: print >> out, '>>',
else: print >> out, ' ',
print >> out, repr(i).rjust(4),
print >> out, opname[op].ljust(15),
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256
i = i+2
print >> out, repr(oparg).rjust(5),
if op in hasconst:
if constants:
print >> out, '(' + repr(constants[oparg]) + ')',
else:
print >> out, '(%d)'%oparg,
elif op in hasname:
if names is not None:
print >> out, '(' + names[oparg] + ')',
else:
print >> out, '(%d)'%oparg,
elif op in hasjrel:
print >> out, '(to ' + repr(i + oparg) + ')',
elif op in haslocal:
if varnames:
print >> out, '(' + varnames[oparg] + ')',
else:
print >> out, '(%d)' % oparg,
elif op in hascompare:
print >> out, '(' + cmp_op[oparg] + ')',
print >> out
def findlabels(code):
"""Detect all offsets in a byte code which are jump targets.
Return the list of offsets.
"""
labels = []
n = len(code)
i = 0
while i < n:
c = code[i]
op = ord(c)
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256
i = i+2
label = -1
if op in hasjrel:
label = i+oparg
elif op in hasjabs:
label = oparg
if label >= 0:
if label not in labels:
labels.append(label)
return labels
def findlinestarts(code):
"""Find the offsets in a byte code which are start of lines in the source.
Generate pairs (offset, lineno) as described in Python/compile.c.
"""
byte_increments = [ord(c) for c in code.co_lnotab[0::2]]
line_increments = [ord(c) for c in code.co_lnotab[1::2]]
lastlineno = None
lineno = code.co_firstlineno
addr = 0
for byte_incr, line_incr in zip(byte_increments, line_increments):
if byte_incr:
if lineno != lastlineno:
yield (addr, lineno)
lastlineno = lineno
addr += byte_incr
lineno += line_incr
if lineno != lastlineno:
yield (addr, lineno)
class FakeFile(object):
def __init__(self):
self.store = []
def write(self, data):
self.store.append(data)
a = lambda x : x
b = lambda x : x # True
c = lambda x : 2 * x
d = lambda y : 2 * y # True
e = lambda x : 2 * x
f = lambda x : x * 2 # True or False is fine, but must be stable
g = lambda x : 2 * x
h = lambda x : x + x # True or False is fine, but must be stable
funcs = a, b, c, d, e, f, g, h
outs = []
for func in funcs:
out = FakeFile()
dis(func)
outs.append(out.store)
import ast
def outfilter(out):
for i in out:
if i.strip().isdigit():
continue
if '(' in i:
try:
ast.literal_eval(i)
except ValueError:
i = "(x)"
yield i
processed_outs = [(out, 'LOAD_GLOBAL' in out or 'LOAD_DECREF' in out)
for out in (''.join(outfilter(out)) for out in outs)]
for (out1, polluted1), (out2, polluted2) in zip(processed_outs[::2], processed_outs[1::2]):
print 'Bytecode Equivalent:', out1 == out2, '\nPolluted by state:', polluted1 or polluted2
Выходные данные True, True, False и Falseи стабильно."Загрязненный" bool имеет значение true, если выходной сигнал будет зависеть от внешнего состояния - глобального состояния или замыкания.