找出列表中重复的元素及个数

方法一： 将数组转成集合，然后循环
data = [1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9]
lis = set(data)
for i in lis:
    if data.count(i) > 1:
        print('data数组中重复的元素是%d，它的个数是%d个' % (i, data.count(i)))

方法二： 定义空字典，将value的值大于1的添加到空字典里，然后循环字典的key和value
data = [1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9]
a = {}
for i in data:
    if data.count(i) > 1:
        a[i] = data.count(i)  # i是key，data.count(i)是value
for j, k in a.items():
    print('data数组中重复的元素有%d，它的个数是%d个' % (j, k))

方法三： 不用count方法，循环判断空字典里如果有key，就对该key的value加1，没有key就让该key的value等于1，可以用while循环，也可以for循环
def get_element(data):
    dic = {}
    i = 0
    while i < len(data):
        if data[i] in dic:
            dic[data[i]] += 1
        else:
            dic[data[i]] = 1
        i += 1
    for j, k in dic.items():
        if k > 1:
            print('data数组中重复的元素有%d，它的个数是%d个' % (j, k))


my_list = [1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4]
get_element(my_list)

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def get_element(data):
    dic = {}
    for i in range(len(data)):
        if data[i] in dic:
            dic[data[i]] += 1
        else:
            dic[data[i]] = 1
    for k, v in dic.items():
        if v > 1:
            print('列表中重复的元素是：%d，数量是%d' % (k, v))


data_list = [1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9]
get_element(data_list)