我有两本字典,但为了简化起见,我就选这两本:

>>> x = dict(a=1, b=2)
>>> y = dict(a=2, b=2)

现在,我想比较x中的每个键值对在y中是否有相同的对应值,所以我这样写:

>>> for x_values, y_values in zip(x.iteritems(), y.iteritems()):
        if x_values == y_values:
            print 'Ok', x_values, y_values
        else:
            print 'Not', x_values, y_values

它的工作原理是返回一个元组,然后比较是否相等。

我的问题:

这对吗?还有更好的办法吗?最好不是在速度上,我说的是代码优雅。

更新:我忘了提到,我必须检查有多少键,值对是相等的。


当前回答

由于似乎没有人提到deepdiff,为了完整起见,我将在这里添加它。我发现它非常方便获得(嵌套)对象的差异:

安装

pip install deepdiff

示例代码

import deepdiff
import json

dict_1 = {
    "a": 1,
    "nested": {
        "b": 1,
    }
}

dict_2 = {
    "a": 2,
    "nested": {
        "b": 2,
    }
}

diff = deepdiff.DeepDiff(dict_1, dict_2)
print(json.dumps(diff, indent=4))

输出

{
    "values_changed": {
        "root['a']": {
            "new_value": 2,
            "old_value": 1
        },
        "root['nested']['b']": {
            "new_value": 2,
            "old_value": 1
        }
    }
}

注意关于检查结果的漂亮打印:如果两个字典具有相同的属性键(可能与示例中的属性值不同),上面的代码就可以工作。但是,如果存在一个“extra”属性是字典之一,json.dumps()将失败

TypeError: Object of type PrettyOrderedSet is not JSON serializable

解决方案:使用diff.to_json()和json.loads() / json.dumps()来漂亮地打印:

import deepdiff
import json

dict_1 = {
    "a": 1,
    "nested": {
        "b": 1,
    },
    "extra": 3
}

dict_2 = {
    "a": 2,
    "nested": {
        "b": 2,
    }
}

diff = deepdiff.DeepDiff(dict_1, dict_2)
print(json.dumps(json.loads(diff.to_json()), indent=4))  

输出:

{
    "dictionary_item_removed": [
        "root['extra']"
    ],
    "values_changed": {
        "root['a']": {
            "new_value": 2,
            "old_value": 1
        },
        "root['nested']['b']": {
            "new_value": 2,
            "old_value": 1
        }
    }
}

替代方案:使用pprint,结果是不同的格式:

import pprint

# same code as above

pprint.pprint(diff, indent=4)

输出:

{   'dictionary_item_removed': [root['extra']],
    'values_changed': {   "root['a']": {   'new_value': 2,
                                           'old_value': 1},
                          "root['nested']['b']": {   'new_value': 2,
                                                     'old_value': 1}}}

其他回答

在Python 3.6中,可以这样做:-

if (len(dict_1)==len(dict_2): 
  for i in dict_1.items():
        ret=bool(i in dict_2.items())

如果dict_1中的所有项都出现在dict_2中,Ret变量将为真

这是我的答案,使用递归的方式:

def dict_equals(da, db):
    if not isinstance(da, dict) or not isinstance(db, dict):
        return False
    if len(da) != len(db):
        return False
    for da_key in da:
        if da_key not in db:
            return False
        if not isinstance(db[da_key], type(da[da_key])):
            return False
        if isinstance(da[da_key], dict):
            res = dict_equals(da[da_key], db[da_key])
            if res is False:
                return False
        elif da[da_key] != db[da_key]:
            return False
    return True

a = {1:{2:3, 'name': 'cc', "dd": {3:4, 21:"nm"}}}
b = {1:{2:3, 'name': 'cc', "dd": {3:4, 21:"nm"}}}
print dict_equals(a, b)

希望有帮助!

如果你想知道在两个字典中有多少值是匹配的,你应该这样说:)

也许是这样的:

shared_items = {k: x[k] for k in x if k in y and x[k] == y[k]}
print(len(shared_items))

下面的代码将帮助您比较python中的dict列表

def compate_generic_types(object1, object2):
    if isinstance(object1, str) and isinstance(object2, str):
        return object1 == object2
    elif isinstance(object1, unicode) and isinstance(object2, unicode):
        return object1 == object2
    elif isinstance(object1, bool) and isinstance(object2, bool):
        return object1 == object2
    elif isinstance(object1, int) and isinstance(object2, int):
        return object1 == object2
    elif isinstance(object1, float) and isinstance(object2, float):
        return object1 == object2
    elif isinstance(object1, float) and isinstance(object2, int):
        return object1 == float(object2)
    elif isinstance(object1, int) and isinstance(object2, float):
        return float(object1) == object2

    return True

def deep_list_compare(object1, object2):
    retval = True
    count = len(object1)
    object1 = sorted(object1)
    object2 = sorted(object2)
    for x in range(count):
        if isinstance(object1[x], dict) and isinstance(object2[x], dict):
            retval = deep_dict_compare(object1[x], object2[x])
            if retval is False:
                print "Unable to match [{0}] element in list".format(x)
                return False
        elif isinstance(object1[x], list) and isinstance(object2[x], list):
            retval = deep_list_compare(object1[x], object2[x])
            if retval is False:
                print "Unable to match [{0}] element in list".format(x)
                return False
        else:
            retval = compate_generic_types(object1[x], object2[x])
            if retval is False:
                print "Unable to match [{0}] element in list".format(x)
                return False

    return retval

def deep_dict_compare(object1, object2):
    retval = True

    if len(object1) != len(object2):
        return False

    for k in object1.iterkeys():
        obj1 = object1[k]
        obj2 = object2[k]
        if isinstance(obj1, list) and isinstance(obj2, list):
            retval = deep_list_compare(obj1, obj2)
            if retval is False:
                print "Unable to match [{0}]".format(k)
                return False

        elif isinstance(obj1, dict) and isinstance(obj2, dict):
            retval = deep_dict_compare(obj1, obj2)
            if retval is False:
                print "Unable to match [{0}]".format(k)
                return False
        else:
            retval = compate_generic_types(obj1, obj2)
            if retval is False:
                print "Unable to match [{0}]".format(k)
                return False

    return retval

迟回复总比不回复好!

比较Not_Equal比比较Equal更有效。因此,如果一个字典中的任何键值在另一个字典中找不到,那么两个字典就不相等。下面的代码考虑到您可能会比较默认的dict,因此使用get而不是getitem[]。

在get调用中使用一种随机值作为默认值,等于要检索的键-以防dicts在一个dict中有None作为值,而该键在另一个dict中不存在。此外,为了提高效率,get !=条件是在not in条件之前检查的,因为您同时对两边的键和值进行检查。

def Dicts_Not_Equal(first,second):
    """ return True if both do not have same length or if any keys and values are not the same """
    if len(first) == len(second): 
        for k in first:
            if first.get(k) != second.get(k,k) or k not in second: return (True)
        for k in second:         
            if first.get(k,k) != second.get(k) or k not in first: return (True)
        return (False)   
    return (True)