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pythonloopsbreak
Drosera_capensis
Drosera_capensis

Reputation: 375

Break a first for loop within a second for loop

I have almost completed a script to compare two lists (listA and listB). The script should return the similar values between the lists, that are following each others, and with single occurrences.

listA=['b', 'c', 'd', 'c', 'c']
listB=['a', 'b', 'c']

    def ordered_matches(list1, list2):
    
    list = []
    
    len1 = len(list1) 
    len2 = len(list2)
    
        start_range = 0
        for f1 in range(len1):
            for f2 in range(start_range, len2):
    
                if list1[f1] == list2[f2] and f2 != len2:      
                    list.append(list1[f1]);
                    start_range = f2;
                    break
                elif list1[f1] == list2[f2] and f2 == len2:
                    list.append(list1[f1]);
                    continue
                    break
        return list
    
    ordered_matches(listA, listB)

Here are examples of input/output expected:

listA=['a', 'b', 'c', 'd', 'e']
listB=['d', 'e', 'f', 'g', 'h']
output=['d','e']

listA=['a', 'b', 'c', 'd', 'e']
listB=['h', 'd', 'g', 'd', 'f']
output=['d']

listA=['b', 'a', 'c', 'a', 'e']
listB=['b', 'a', 'e', 'b', 'e']
output=['b', 'a', 'e']

To reach this result, the first for loop of the script should be broken. But unfortunately, I can't manage to break the first for loop within the second for loop.

Would you have any advice to do it?

Upvotes: 0

Views: 64

Answers (1)

Drosera_capensis
Drosera_capensis

Reputation: 375

I think I have found an answer that does not require to break the outer loop. The main question of this topic is not addressed, but at least the script seems to work.

def ordered_matches(list1, list2):

    list = []

    len1 = len(list1)
    len2 = len(list2)

    start_range = 0
    for f1 in range(len1):
            for f2 in range(start_range, len2):

                if list1[f1] == list2[f2]:      
                    list.append(list1[f1]);
                    start_range = f2+1;
                    break
    return list

However, it is noticeable that the position of the inputs in the command can change the outputs.

Upvotes: 1

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