根据其值反转字典的部分

Question

我是 Python 的新手，我正在尝试使用词典进行不同的尝试。我有疑惑如何将前面所有项的顺序倒序为一个值大于10

的项

Input: [1 : value1, 2 : value2, 3 : value3, 4 : value4], knowing that (value3 * 2) > 10
Output : [1 : value2, 2 : value1, 3 : value3, 4 : value4]

结合字典中的真实例子：

Input :  {0: 1, 1: 4, 2: 6, 3: 1, 4: 2}

Output : {0: 4, 1: 1, 2: 6, 3: 1, 4: 2}

如果有多个数字，我希望每组项目都反转：

Input :  {0: 1, 1: 4, 2: 6, 3: 2, 4: 1, 5: 6, 6: 1, 7: 2}

Output : {0: 4, 1: 1, 2: 6, 3: 1, 4: 2, 5: 6, 6: 1, 7: 2}

Answer 1

您似乎混淆了集合和列表。如果是列表，解决方案将是：

def map_reverse_partial(A):
    start = 0
    for index, ele in enumerate(A):
        if 2 * ele >= 16:
            A[start:index + 1] = reversed(A[start:index + 1])
            start = index + 1
    return A

如果是地图，解决方案将是：

def map_reverse_partial(A):
    start = 0
    for index, ele in enumerate(A.values()):
        if 2 * ele > 10:
            if index > start + 1:
                for i in range(start, (start + index - 1)//2 + 1):
                    A[i], A[start + index - 1  - i] = A[start + index - 1  - i], A[i]
        start = index + 1
    return A

Answer 2

def swapper(d):
    keys = []
    values = []
    for p in d:
        if p*d[p] > 10:
            values.reverse() # reverse the order of values
            for k,v in zip(keys, values): # update values
                d[k] = v
            keys = [] # empty the keys and values lists
            values = []
        else: # keep track of the things we will need to swap
            keys.append(p)
            values.append(d[p])
    return d

根据其值反转字典的部分

Reversed parts of a dictionary according to its values

python

reverse

dictionary