我正在研究一个 Python 类，其结构类似于此答案中的示例：https ://stackoverflow.com/a/1383744/576333 。该类本身使用字典跟踪所有创建的对象。
class Repository(object):
# All repositories are stored in this class-level dictionary such that
# all instances of this class maintain the same set.
all_repos = {}
def __init__(self, name, data):
"""
Create a repository object. If it has the required tags, include it in
the collection of all repositories.
"""
# Don't add it if it already exists
if not name in Repository.all_repos:
# Store the attributes
self.__dict__ = data
self.__dict__['name'] = name
Repository.all_repos.update({ name: self })
我的问题是当我创建一个删除/删除方法并想Repository从all_repos字典中清除一个实例时，python 中会发生什么？这是我计划做这样的方法：
def remove(self):
repo = Repository.all_repos.pop(self.name) # pop it out
print "You just removed %s" % repo.name
具有以下用法：
a= Repository('repo_name', {'attr1':'attr1_value',...}
a.remove()
此时，a仍然存在，但不在Repository.all_repos. Python 什么时候会最终移除a？