Python class for tracking access to members of collections. Great for legacy code were we wonder "what's being accessed in this big dict and where is it being accessed?"

collection_access_tracker.py

from __future__ import print_function
import inspect
import six


def fmt_stack(frames):
    s = ""
    for f in frames[::-1]:
        s += "{}:{}: {}\n".format(f[1], f[2], '\\n'.join([x.replace('\n', '') for x in f[4]]))
    return s


def print_access(item, context):
    s = '.'.join([str(x) for x in context])
    s = '{} = {}'.format(s, str(item))
    print('\n', s, '\n', fmt_stack(inspect.stack()[2:]), '\n\n\n')
    return s

class CollectionAccessTracker(object):
    def __init__(self, item, context=None):
        self.item = item
        self.context = context if context else list()

    def __getattribute__(self, name):
        ctx = object.__getattribute__(self, 'context') + [name]
        val = object.__getattribute__(self, 'item').__getattribute__(name)
        if isinstance(val, six.string_types) or isinstance(val, (int, float, long, complex)) or isinstance(val, bool):
            print_access(val, ctx)
            return val
        return CollectionAccessTracker(val, ctx)

    def __getitem__(self, name):
        ctx = object.__getattribute__(self, 'context') + [name]
        val = object.__getattribute__(self, 'item')[name]
        if isinstance(val, six.string_types) or isinstance(val, (int, float, long, complex)) or isinstance(val, bool):
            print_access(val, ctx)
            return val
        return CollectionAccessTracker(val, ctx)

    def __contains__(self, name):
        return name in object.__getattribute__(self, 'item')

    def __str__(self):
        return str(object.__getattribute__(self, 'item'))

    @property
    def __class__(self):
        cls = object.__getattribute__(self, 'item').__class__
        print('\n\n', cls, '\n')
        return cls

    def __repr__(self):
        return str(self.__class__) + repr(object.__getattribute__(self, 'item'))

    def toJSON(self):
        return self.item