两个列表之间的模式匹配-Python

Question

i have a bunch of zip files in a directory and would like to get notified if one of them is missing .

Example code:

a = ['pattern1.zip', 'pattern2.zip', 'pattern3.zip']
b = []
for root,dirs,files in os.walk(some_path):
    for i in files:
        if i.endswith(('pattern1.zip', 'pattern2.zip', 'pattern3.zip')):
            b.append(i)

Output: b = ['test-pattern1.zip', 'test-pattern2.zip', 'test-pattern3.zip']

would like to match the contents of 'b' with 'a' and check if any of the zip files are missing

Answer 1

I would take a different approach:

patterns = {'pattern1.zip', 'pattern2.zip', 'pattern3.zip'}
for root, dirs, files in os.walk(some_path):
    for f in files:
        for pattern in patterns:
            if f.endswith(pattern):
                patterns.remove(pattern)
                break

print('Missing patterns:', patterns)

Answer 2

You can convert the lists to sets and take their difference 1 :

files_that_should_be_present = ['pattern1.zip', 'pattern2.zip', 'pattern3.zip']
files_that_are_present = ['pattern1.zip', 'pattern2.zip']

files_missing = list(set(files_that_should_be_present) - set(files_that_are_present))
print(files_missing)

Outputs: ['pattern3.zip']