Question

我正在尝试相互对照两个字典。目的是确认list1中的country也存在于list2中。如果不存在，则应打印country不存在（如果存在），它将打印出该国家存在。

两个列表均以国家/地区开头，但长度随键和值的不同而不同，如下所示。

list1 = [{ 'country': 'brazl', 'state': 'oregon'}, { 'country': 'japan', 'state': 'chicago'}, { 'country': 'australia', 'state': 'washington', 'water': 'clean'} { 'country':'china']
list2 = ...

Answer 1

例如，您可以将列表1中的所有国家/地区设为一组，而将列表2中的国家/地区设为另一组：

countries1 = set(item.get("country", "unknown") for item in list1)
countries2 = set(item.get("country", "unknown") for item in list2)

然后将两者区别开来：

print("countries in list1 but not in list2:")
print(countries1 - countries2)

或工会：

print("countries in list1 and in list2:")
print(countries1 & countries2)

Answer 2

制作每个列表中存在的国家/地区集，然后减去它们，从而在list1中（而不是list2）中有一组国家/地区，例如：

missing_countries = set([i['country'] for i in list1]) - set([i['country'] for i in list2])
print("Countries not in list2:")
for i in missing_countries:
    print(i)

Answer 3

countries1 = list(item['country'] for item in list1)
countries2 = list(item['country'] for item in list2)
compare1 = [country for country in countries1 if country not in countries2] # doesnt exist
compare2 = [country for country in countries1 if country in countries2] # exist

案例状态：

state1 = list(item['state'] for item in list1)
state2 = list(item['state'] for item in list2)
compare1 = [state for state in state1 if state not in state2] # doesnt exist

更新的代码：

list1 = [{ 'country': 'brazil', 'state': 'oregon' , 'some_key': 'some _value'}, { 'country': 'japan', 'state': 'chicago'}, { 'country': 'australia', 'state': 'washington', 'water': 'clean'}, { 'country':'china', 'state':'Tokio'}]

list2 = [{ 'country': 'brazil', 'state': 'oregon'}, { 'country': 'america', 'state': 'new york'}, { 'country': 'australia', 'state': 'washington', 'water': 'clean'},{ 'country':'china'}]


def check_key(dict_key):
    # Check if key exist in all dictionaries
    for item in list1+list2:
        if dict_key in item.keys():
            status = True
        else:
            status = False
            return status

    return status


# If key exist in all dictionaries compare
# If key doesnt exist in all dictionaries skip to next key
for k in list1[0].keys():
    # Ckeck if key exist in all dictionaries
    status = check_key(k)
    # test
    #print ("key: {}, exist in all".format(k)) if status else print ("key: {}, doesn't exist in all".format(k)) # key: country, exist in all
    if status: # True
        # If key exist in all dictionaries
        values1 = list(item[k] for item in list1)
        values2 = list(item[k] for item in list2)
        compare1 = [country for country in values1 if country not in values2]  # doesnt exist
        print ("For key: {}, values which doesnt exist in list2: {}".format(k,compare1))
        compare2 = [country for country in countries1 if country in countries2]  # exist
        print("For key: {}, values which exist in list2: {}".format(k, compare2))
    else: # False
        # If key doesnt exist in all dictionaries
        pass

输出：

For key: country, values which doesnt exist in list2: ['japan']
For key: country, values which exist in list2: ['brazil', 'australia', 'china']

更新代码2 :)：

list1 = [{ 'country': 'brazl', 'state': 'oregon'}, { 'country': 'japan', 'state': 'chicago'}, { 'country': 'australia', 'state': 'washington', 'water': 'clean'},{'country':'china'}]

for item in list1:
    if 'state' in item.keys():
        print (item['state'])

输出：

oregon
chicago
washington

Python3检查针对另一个命令的列表

3 个答案: