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统计另一个方法中的python方法调用

profiling python

job · 技术社区 · 16 年前

我实际上是在用Java做这件事,但我正在自学python,这让我想知道是否有一种简单/聪明的方法可以用包装器或其他东西来做到这一点。

我想知道一个特定方法在另一个方法中被调用了多少次。例如:

def foo(z):
    #do something
    return result

def bar(x,y):
    #complicated algorithm/logic involving foo
    return foobar

>>> print bar('xyz',3)
foo was called 15 times
[results here]
>>> print bar('stuv',6)
foo was called 23 times
[other results here]

编辑:我意识到我可以在酒吧里拍一个柜台,回来后把它扔掉,但如果你能用包装纸做一些魔法来完成同样的事情,那就太酷了。这也意味着我可以在其他地方重用相同的包装器,而无需修改方法内的任何代码。

3 回复 | 直到 16 年前

jmd_dk 8 年前

听起来几乎是装饰师的教科书示例!

def counted(fn):
    def wrapper(*args, **kwargs):
        wrapper.called += 1
        return fn(*args, **kwargs)
    wrapper.called = 0
    wrapper.__name__ = fn.__name__
    return wrapper

@counted
def foo():
    return

>>> foo()
>>> foo.called
1

你甚至可以使用另一个装饰器来自动记录一个函数在另一个函数内被调用的次数:

def counting(other):
    def decorator(fn):
        def wrapper(*args, **kwargs):
            other.called = 0
            try:
                return fn(*args, **kwargs)
            finally:
                print '%s was called %i times' % (other.__name__, other.called)
        wrapper.__name__ = fn.__name__
        return wrapper
    return decorator

@counting(foo)
def bar():
    foo()
    foo()

>>> bar()
foo was called 2 times

foo 或 bar 不过,最终可能会调用自己,您需要一个涉及堆栈的更复杂的解决方案来处理递归。然后,你将走向一个全面的分析器。..

如果你还在自学Python,那么这种包装好的装饰材料可能不是理想的选择,因为它往往被用于魔法!

Ned Batchelder 16 年前

这定义了一个装饰器来完成它:

def count_calls(fn):
    def _counting(*args, **kwargs):
        _counting.calls += 1
        return fn(*args, **kwargs)
    _counting.calls = 0
    return _counting

@count_calls
def foo(x):
    return x

def bar(y):
    foo(y)
    foo(y)

bar(1)
print foo.calls

Anon 16 年前

import inspect

def make_decorators():
    # Mutable shared storage...
    caller_L = []
    callee_L = []
    called_count = [0]
    def caller_decorator(caller):
        caller_L.append(caller)
        def counting_caller(*args, **kwargs):
            # Returning result here separate from the count report in case
            # the result needs to be used...
            result = caller(*args, **kwargs)
            print callee_L[0].__name__, \
                   'was called', called_count[0], 'times'
            called_count[0] = 0
            return result
        return counting_caller

    def callee_decorator(callee):
        callee_L.append(callee)
        def counting_callee(*args, **kwargs):
            # Next two lines are an alternative to
            # sys._getframe(1).f_code.co_name mentioned by Ned...
            current_frame = inspect.currentframe()
            caller_name = inspect.getouterframes(current_frame)[1][3]
            if caller_name == caller_L[0].__name__:
                called_count[0] += 1
            return callee(*args, **kwargs)
        return counting_callee

    return caller_decorator, callee_decorator

caller_decorator, callee_decorator = make_decorators()

@callee_decorator
def foo(z):
    #do something
    return ' foo result'

@caller_decorator
def bar(x,y):
    # complicated algorithm/logic simulation...
    for i in xrange(x+y):
        foo(i)
    foobar = 'some result other than the call count that you might use'
    return foobar


bar(1,1)
bar(1,2)
bar(2,2)

这是输出(用Python 2.5.2测试):

foo was called 2 times
foo was called 3 times
foo was called 4 times