Python parsing a list of strings through another list and return matches

Question

I have two text files that I have turned into lists. List1 has lines that look like this:

'U|blah|USAA032812134||blah|blah|25|USAA032812134|blah|A||4||blah|2019-05-28 12:54:59|blah|123456||blah'

list2 has lines that look like this:

['smuspid\n', 'USAA032367605\n', 'USAA032367776\n', 'USAA044754265\n', 'USAA044754267\n']

I want to return every line in list1 that has a match in list2. I've tried using regex for this:

found = []
check = re.compile('|'.join(list2))
for elem in list1:
    if check.match(elem):
        found.append(elem)

but my code above is returning an empty list. Any suggestions?

you want match or exact equal

Ryuzaki L
– Ryuzaki L

2019-11-09 00:06:00 +00:00
Commented Nov 9, 2019 at 0:06 — Ryuzaki L
– Ryuzaki L, Commented Nov 9, 2019 at 0:06

Emma Marcier · Accepted Answer · 2019-11-09 00:53:30Z

2

I guess you can do that without a regular expression:

Method 1

list1 = ['U|blah|USAA032812134||blah|blah|25|USAA032812134|blah|A||4||blah|2019-05-28 12:54:59|blah|123456||blah']

list2 = ['|USAA032812134', '|USAA0328121304', '|USAA032999812134']

found = []
for i in list1:
    for j in list2:
        if j in i:
            found.append(j)

print(found)

Output 1

['|USAA032812134']

Method 2 using List Comprehension

list1 = ['U|blah|USAA032812134||blah|blah|25|USAA032812134|blah|A||4||blah|2019-05-28 12:54:59|blah|123456||blah']
list2 = ['|USAA032812134', '|USAA0328121304', '|USAA032999812134', 'blah']

print([j for i in list1 for j in list2 if j in i])

Output 2

['|USAA032812134', 'blah']

Method 3: `strip()` for new lines

You can simply strip() and append() to your found list:

list1 = ['U|blah|USAA032812134||blah|blah|25|USAA032812134|blah|A||4||blah|2019-05-28 12:54:59|blah|123456||blah']
list2 = ['smuspid\n', 'USAA032812134\n', 'USAA032367605\n', 'USAA032367776\n',
         'USAA044754265\n', 'USAA044754267\n']

found = []
for i in list1:
    for j in list2:
        if j.strip() in i:
            found.append(j.strip())

print(found)

Output 3

['USAA032812134']

edited Nov 9, 2019 at 0:53

answered Nov 9, 2019 at 0:15

Emma Marcier

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1 Comment

lagn91 Over a year ago

Sorry, list2 has a different format than what I previously thought, I edited the question to show what the elements look like. Does that change your code because this method still returned an empty list when I tried it.

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Python parsing a list of strings through another list and return matches

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Method 2 using List Comprehension

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Method 3: `strip()` for new lines

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Method 3: `strip()` for new lines