How to check if enough specific elements are in a list?

July 18, 2022

I am trying to check if at least five items in my list have the following format: r"P\d+:Q\d+". So, these are accepted:

P14:Q52
P32:Q65
P1000:Q23423
:
:
etc.

I have a list of cell ranges like below:

mcr_coord_lst = [mcr.coord for mcr in worksheet.merged_cells.ranges]

mcr_coord_lst
['P58239:Q58239',
 'P58234:Q58234',
 'P58235:Q58235',
 'P58236:Q58236',
 'P58237:Q58237',
 'P58238:Q58238',
 'P58229:Q58229',
 'P58230:Q58230',
 'P58231:Q58231',
 'P58232:Q58232',
 'P58233:Q58233',
 'P58224:Q58224',
 'P58225:Q58225',
 'P58226:Q58226',
:
:
 'A123:Q324234',
:
:
]

I set up a counter and add to the counter if the item in my list matches pq_columns = re.compile(r"P\d+:Q\d+"). If the counter >= 5, then I break the loop and return 'Yes'. However, this result is returning 'Yes'for all of the items in my list and I am not sure what I am doing wrong.

counter = 0
is_in = False
while is_in == False:
    for item in mcr_coord_lst:
        if pq_columns.match(item):
            counter += 1
            if counter >= 5:
                print('Yes')
                is_in = True
        else:
            print('No')
            break

This code outputs:

Yes
Yes
...
Yes
Yes
Yes
:
:

Can you help me fix my code? Or do you recommend another way to do what I am trying to do?

>Solution :

Using a list comprehension we can try:

lst_filter = [x for x in mcr_coord_lst if re.search(r'^P\d+:Q\d+$', x)]
if len(lst_filter) >= 5:
    print("list is valid")
else:
    print("list is not valid")