Python 如何将字典对象值从一个键复制到另一个键？

我必须用输入制作一个字典，它可能包含“键->值1，值2”或“键->键”。 键始终是字符串，值始终是整数，由逗号和空格分隔。 如果给定一个键和值，我必须将这些值存储到给定的键。 如果密钥已经存在，我必须将给定值添加到旧值中。 如果给定一个键和另一个键，我必须将另一个键的值复制到第一个键。 如果另一个键不存在，则必须忽略此输入行。 当我收到命令“end”时，我必须停止读取输入行，并且必须以以下格式打印所有键及其值： {key}==={value1，value2，value3}

data=input（）
dict_ref={}
def为_int（s）：
尝试：
int（s）
返回真值
除值错误外：
返回错误
而数据！=“结束”：
列表\数据=数据。拆分（“->”）
名称=列表\数据[0]
值=列表\数据[1]。拆分（“，”）
如果名称不在dict_ref中且为_int（值[0]）：
dict_ref[name]=值
dict_ref中的elif值[0]：
dict_ref[name]=dict_ref[value[0]]
在dict_ref中的elif名称和is_int（值[0]）：
dict_ref[name].extend（值）
数据=输入（）
对于dict_ref中的项目：
打印（f“{item}==”，end=”“）
打印（“，”。连接（dict_ref[项目]）

输入：

彼得->1，2，3

ISAC->Peter

彼得->4，5

结束

预期产出：

彼得===1,2,3,4,5

data = input()

dict_ref = {}


def is_int(s):

try:
    int(s)
    return True
except ValueError:
    return False

while data != 'end':
    list_data = data.split('->')
    key = list_data[0].strip()
    values = list_data[1].split(',')

    for value in values:
        value = value.strip()

        if key not in dict_ref.keys() and is_int(value):
            dict_ref[key] = [value]

        elif key in dict_ref.keys() and is_int(value):
            dict_ref[key].append(value)

        else:
        '''
        With Python dictionaries, when you assign a key to the value of another, the refresh is done automatically.
        For example, writing in this condition, dict_ref [key] = dict_ref [value], when the while loop will start with a new data value, 
        dict_ref [key] = dict_ref [value] will be dynamically updated with the new data as well.
        That's why you should not make a direct assignment, you have to create a new variable that will contain Peter's values,
        then you will assign to the key 'Isacc'.
        '''
            vals = list() #New List
            for val in dict_ref[value]:
                vals.append(val)
            dict_ref[key] = vals

    data = input()

for item in dict_ref:
    print(f"{item} === ", end="")
    print(", ".join(dict_ref[item]))

Isacc==1,2,3

实际产量：

彼得===1,2,3,4,5

data = input()

dict_ref = {}


def is_int(s):

try:
    int(s)
    return True
except ValueError:
    return False

while data != 'end':
    list_data = data.split('->')
    key = list_data[0].strip()
    values = list_data[1].split(',')

    for value in values:
        value = value.strip()

        if key not in dict_ref.keys() and is_int(value):
            dict_ref[key] = [value]

        elif key in dict_ref.keys() and is_int(value):
            dict_ref[key].append(value)

        else:
        '''
        With Python dictionaries, when you assign a key to the value of another, the refresh is done automatically.
        For example, writing in this condition, dict_ref [key] = dict_ref [value], when the while loop will start with a new data value, 
        dict_ref [key] = dict_ref [value] will be dynamically updated with the new data as well.
        That's why you should not make a direct assignment, you have to create a new variable that will contain Peter's values,
        then you will assign to the key 'Isacc'.
        '''
            vals = list() #New List
            for val in dict_ref[value]:
                vals.append(val)
            dict_ref[key] = vals

    data = input()

for item in dict_ref:
    print(f"{item} === ", end="")
    print(", ".join(dict_ref[item]))

Isacc==1,2,3,4,5

data = input()

dict_ref = {}


def is_int(s):

try:
    int(s)
    return True
except ValueError:
    return False

while data != 'end':
    list_data = data.split('->')
    key = list_data[0].strip()
    values = list_data[1].split(',')

    for value in values:
        value = value.strip()

        if key not in dict_ref.keys() and is_int(value):
            dict_ref[key] = [value]

        elif key in dict_ref.keys() and is_int(value):
            dict_ref[key].append(value)

        else:
        '''
        With Python dictionaries, when you assign a key to the value of another, the refresh is done automatically.
        For example, writing in this condition, dict_ref [key] = dict_ref [value], when the while loop will start with a new data value, 
        dict_ref [key] = dict_ref [value] will be dynamically updated with the new data as well.
        That's why you should not make a direct assignment, you have to create a new variable that will contain Peter's values,
        then you will assign to the key 'Isacc'.
        '''
            vals = list() #New List
            for val in dict_ref[value]:
                vals.append(val)
            dict_ref[key] = vals

    data = input()

for item in dict_ref:
    print(f"{item} === ", end="")
    print(", ".join(dict_ref[item]))

输入：

彼得->1，2，3

ISAC->Peter

彼得->4，5

结束

输出：

彼得===1,2,3,4,5

data = input()

dict_ref = {}


def is_int(s):

try:
    int(s)
    return True
except ValueError:
    return False

while data != 'end':
    list_data = data.split('->')
    key = list_data[0].strip()
    values = list_data[1].split(',')

    for value in values:
        value = value.strip()

        if key not in dict_ref.keys() and is_int(value):
            dict_ref[key] = [value]

        elif key in dict_ref.keys() and is_int(value):
            dict_ref[key].append(value)

        else:
        '''
        With Python dictionaries, when you assign a key to the value of another, the refresh is done automatically.
        For example, writing in this condition, dict_ref [key] = dict_ref [value], when the while loop will start with a new data value, 
        dict_ref [key] = dict_ref [value] will be dynamically updated with the new data as well.
        That's why you should not make a direct assignment, you have to create a new variable that will contain Peter's values,
        then you will assign to the key 'Isacc'.
        '''
            vals = list() #New List
            for val in dict_ref[value]:
                vals.append(val)
            dict_ref[key] = vals

    data = input()

for item in dict_ref:
    print(f"{item} === ", end="")
    print(", ".join(dict_ref[item]))

---

Isacc===1,2,3

“预期输出”有哪些输入？在您的示例输入中，我看不到Peter和Isaac。很抱歉，我添加了它。非常感谢@Sekouba，这解决了我的问题。我只需添加检查dict.ref.keys（）中是否存在“值”（如果是字符串），如果不存在则传递。