AFAIK, when allow_playback_repeats is False, the number of requests should be equal to the length of cassette data.
But when we use new_episodes mode with same/matched requests called several times, the number of cassette data is smaller than the number of requests.

This is the same problem as mentioned here: #245
I changed the reproduce script to httpx so it's easier to count the number of requests:
https://colab.research.google.com/gist/vickyliin/cf06ea0dc0f7f2f8a1b5c30bb8f3909d/vcrpy-bug.ipynb

In the new_episodes context, the number of reuqests is 7, while the length of cassette.data is only 4

The cause is cassette.append doesn't set play_counts just like #245 mentioned. When a new and matched request calls, it uses the previously appended cassette data. So the total number of cassette.data for the above script is 1 (old) + 6/2 (new episodes) = 4

For now I use the following code as a hotfix:

class FixedCassette(Cassette):
    def append_and_play(self, request, response) -> None:
        prev_len_data = len(self.data)
        super().append(request, response)
        is_appended = len(self.data) == prev_len_data + 1
        if is_appended:
            self.play_counts[prev_len_data] += 1

    def _load(self) -> None:
        super()._load()
        self.append = self.append_and_play
        self._load = None


context = vcr.use_cassette(...)
context.cls = FixedCassette
wich context:
    run_requests()

Related code:

Records are only used when no play_count

append does not set play_count

append is also used when loading cassette so we can't set play_count in append directly

For other modes, we can't see this problem because rewound is False (or it's ALL mode)