你可以使用开源ndicts包中的NestedDict(我是作者)，它有一个完全像字典一样的安全get方法。

>>> from ndicts import NestedDict
>>> nd = NestedDict({"key1": {"key2": 0}}
>>> nd.get(("key1", "key2))
0
>>> nd.get("asd")

因为如果缺少一个键就会引发一个键错误是合理的，我们甚至可以不检查它，让它像这样单一:

def get_dict(d, kl):
  cur = d[kl[0]]
  return get_dict(cur, kl[1:]) if len(kl) > 1 else cur

我建议你试试蟒蛇本尼迪克特。

它是一个dict子类，提供小键盘支持等功能。

安装:pip install python-benedict

from benedict import benedict

example_dict = benedict(example_dict, keypath_separator='.')

现在你可以使用keypath访问嵌套值:

val = example_dict['key1.key2']

# using 'get' method to avoid a possible KeyError:
val = example_dict.get('key1.key2')

或者使用键列表访问嵌套值:

val = example_dict['key1', 'key2']

# using get to avoid a possible KeyError:
val = example_dict.get(['key1', 'key2'])

它在GitHub上经过了很好的测试和开源:

https://github.com/fabiocaccamo/python-benedict

注:我是这个项目的作者

在第一阶段，你可以得到一个空字典。

example_dict.get('key1',{}).get('key2')

已经有很多很好的答案，但我已经提出了一个类似于JavaScript领域的lodash get的函数，它也支持通过索引进入列表:

def get(value, keys, default_value = None):
'''
    Useful for reaching into nested JSON like data
    Inspired by JavaScript lodash get and Clojure get-in etc.
'''
  if value is None or keys is None:
      return None
  path = keys.split('.') if isinstance(keys, str) else keys
  result = value
  def valid_index(key):
      return re.match('^([1-9][0-9]*|[0-9])$', key) and int(key) >= 0
  def is_dict_like(v):
      return hasattr(v, '__getitem__') and hasattr(v, '__contains__')
  for key in path:
      if isinstance(result, list) and valid_index(key) and int(key) < len(result):
          result = result[int(key)] if int(key) < len(result) else None
      elif is_dict_like(result) and key in result:
          result = result[key]
      else:
          result = default_value
          break
  return result

def test_get():
  assert get(None, ['foo']) == None
  assert get({'foo': 1}, None) == None
  assert get(None, None) == None
  assert get({'foo': 1}, []) == {'foo': 1}
  assert get({'foo': 1}, ['foo']) == 1
  assert get({'foo': 1}, ['bar']) == None
  assert get({'foo': 1}, ['bar'], 'the default') == 'the default'
  assert get({'foo': {'bar': 'hello'}}, ['foo', 'bar']) == 'hello'
  assert get({'foo': {'bar': 'hello'}}, 'foo.bar') == 'hello'
  assert get({'foo': [{'bar': 'hello'}]}, 'foo.0.bar') == 'hello'
  assert get({'foo': [{'bar': 'hello'}]}, 'foo.1') == None
  assert get({'foo': [{'bar': 'hello'}]}, 'foo.1.bar') == None
  assert get(['foo', 'bar'], '1') == 'bar'
  assert get(['foo', 'bar'], '2') == None

你可以使用pydash:

import pydash as _  #NOTE require `pip install pydash`

_.get(example_dict, 'key1.key2', default='Default')

https://pydash.readthedocs.io/en/latest/api.html