向列表中添加新项目？

Question

This has been answered and I know how to add items to a list, but for some reason it is not working correctly.

So, there is a .dat file with a list of 5000 songs, each song has random numbers assigned to them. I have preassigned random numbers, and I have to run a loop that finds 10 or so songs with similar numbers and put those in a list. I set a maximum of 10 to the list.

But when I use extend() it only adds the very last song that was scanned. I have no idea why its doing this.

Here's the code:

while True:
    from time import sleep
    matchList = []
    SongAttributes = myMusic.getSongAttributes(num)
    print(SongAttributes)
    num += 1
    sleep(0)
    if set(likedAttributes) & set(SongAttributes):
        matchList.extend(SongAttributes)
        count += 1
        if count > 10:
            print('List:')
            print(matchList)
            break

Answer 1

Every time the matchList = [] line is run, the matchList is reset. In the question code, it looks like this initialization line is within the while True: loop, which means that every iteration resets the matchList instead of building upon it via the .extend() function. This can be solved by moving that line outside the loop:

matchList = []

while True:
    from time import sleep
    ...
    ...