好吧，这是一种 缓慢的
方法。可以对其进行修改以监视局部变量的更改（仅按名称）。它是这样工作的：我们执行sys.settrace并在每个步骤中分析obj.attr的值。棘手的是，
'line'在执行行之前，我们会收到事件（执行了某些行）。因此，当我们注意到obj.attr发生了变化时，我们已经在下一行，并且无法获得前一行的帧（因为没有为每行复制帧，所以它们被修改了）。因此，在我保存
traceback.format_stack到的每个行事件中
watcher.prev_st，如果在下一次调用
trace_command值发生更改时，我们会将保存的堆栈跟踪打印到文件中。在每一行上保存回溯是相当昂贵的操作，因此您必须设置
include
关键字指向您的项目目录列表（或只是项目的根目录），以免观察其他库的工作方式并浪费cpu。
watcher.py
import tracebackclass Watcher(object): def __init__(self, obj=None, attr=None, log_file='log.txt', include=[], enabled=False): """ Debugger that watches for changes in object attributes obj - object to be watched attr - string, name of attribute log_file - string, where to write output include - list of strings, debug files only in these directories. Set it to path of your project otherwise it will take long time to run on big libraries import and usage. """ self.log_file=log_file with open(self.log_file, 'wb'): pass self.prev_st = None self.include = [incl.replace('\','/') for incl in include] if obj: self.value = getattr(obj, attr) self.obj = obj self.attr = attr self.enabled = enabled # important, must be last line on __init__. def __call__(self, *args, **kwargs): kwargs['enabled'] = True self.__init__(*args, **kwargs) def check_condition(self): tmp = getattr(self.obj, self.attr) result = tmp != self.value self.value = tmp return result def trace_command(self, frame, event, arg): if event!='line' or not self.enabled: return self.trace_command if self.check_condition(): if self.prev_st: with open(self.log_file, 'ab') as f: print >>f, "Value of",self.obj,".",self.attr,"changed!" print >>f,"###### Line:" print >>f,''.join(self.prev_st) if self.include: fname = frame.f_pre.co_filename.replace('\','/') to_include = False for incl in self.include: if fname.startswith(incl): to_include = True break if not to_include: return self.trace_command self.prev_st = traceback.format_stack(frame) return self.trace_commandimport syswatcher = Watcher()sys.settrace(watcher.trace_command)testwatcher.py
from watcher import watcherimport numpy as npimport urllib2class X(object): def __init__(self, foo): self.foo = fooclass Y(object): def __init__(self, x): self.xoo = x def boom(self): self.xoo.foo = "xoo foo!"def main(): x = X(50) watcher(x, 'foo', log_file='log.txt', include =['C:/Users/j/PycharmProjects/hello']) x.foo = 500 x.goo = 300 y = Y(x) y.boom() arr = np.arange(0,100,0.1) arr = arr**2 for i in xrange(3): print 'a' x.foo = i for i in xrange(1): i = i+1main()
