当键与多个值关联时，在Python中查找值的键

对于该类型的字典

{'key1': ['v1','v2','v3', ...],
 'key2': ['v2','v4', ...],
  ... }

How do I

1. 查找与值 v 关联的任何键
2. 将 k:[value set] 对打印到新字典中

# answer to 1st question
keys_with_value = [k for k, v in old_dict.iteritems() if "whatever_value" in v]

# answer to 2nd question
new_dict = {}   
for k in keys_with_value:
   new_dict[k] = old_dict[k]

Example:

>>> old_dict = {'key1':['v1','v2','v3'], 'key2':['v2','v4']}
>>> keys_with_value = [k for k, v in old_dict.iteritems() if "v2" in v]
>>> new_dict = {}
>>> for k in keys_with_value:
       new_dict[k] = old_dict[k]

>>> new_dict
{'key2': ['v2', 'v4'], 'key1': ['v1', 'v2', 'v3']}

>>> new_dict = {}
>>> keys_with_other_value = [k for k, v in old_dict.iteritems() if "v1" in v]
>>> for k in keys_with_other_value:
       new_dict[k] = old_dict[k]

>>> new_dict
{'key1': ['v1', 'v2', 'v3']}