计算一个子列表在列表中的次数

Question

I want to know how many times a sublist is in a list next to eachother.

From another question, I received the following code to determinate if a sublist is in a list:

list_sequence = ['Example 64', 'Example 32', 'Example 16']

my_list = ['Example 128', 'Example 64', 'Example 32', 'Example 16', 'Example 256', 'Example 512', 'Example 1024']

print(str(list_sequence)[1:-1] in str(my_list))

But I want to know, how many times the list_sequence is NEXT to each other to determinate a combo. In the top example its 1, but if I would append list_sequence at the start and at the very end, it still would 1. If I would add it right after Example 16 in my_list , it would be 2.

Answer 1

You can use zip and enumerate within a list comprehension to find the respective indices of places where your sub_list occurs. Then select those who's subtraction is equal to 3 (length of sub_list):

In [6]: list_sequence = ['Example 64', 'Example 32', 'Example 16']
   ...: 
   ...: my_list = ['Example 128', 'Example 64', 'Example 32', 'Example 16', 'Example 64', 'Example 32', 'Example 16', 'Example 256', 'Example 512', 'E
   ...: xample 1024','Example 64', 'Example 32', 'Example 16']
   ...: 

In [7]: indices = [index for index, (i, j, k) in enumerate(zip(my_list, my_list[1:], my_list[2:])) if list_sequence == [i, j, k]]
Out[7]: [1, 4, 10]

In [8]: sum(2 * (j-i == len(list_sequence)) for i, j in zip(indices, indices[1:]))
Out[8]: 2

You an only use a generator expression within sum to find the number of occurrences:

In [4]: sum(list_sequence == [i, j, k] for i, j, k in zip(my_list, my_list[1:], my_list[2:]))
Out[4]: 1

But note that this will also include overlaps because zip(my_list, my_list[1:], my_list[2:])) will give you all consequent triples.

Answer 2

Count By creating dictionary of list_sequence

list_sequence = ['Example 64', 'Example 32', 'Example 16']

my_list = ['Example 128', 'Example 64', 'Example 32', 'Example 16','Example 16', 'Example 256', 'Example 512', 'Example 1024']
dic=dict()
for i in list_sequence :
    for j in my_list :
        if i==j:
            dic[i]=dic.get(i,0)+1
print(dic)

{'Example 64': 1, 'Example 32': 1, 'Example 16': 2}