作者james999 (无伤大雅)
看板Python
标题[问题] Python语法问题请益
时间Thu May 2 02:06:21 2019
小弟最近在学Python，
实际应用需要修改网上的范例，
其中看到一段程式码无法理解，
希望板上先进能协助，谢谢。
detections = []
detections = [Detection(bbox, score, feature) for bbox,score, feature in
zip(detections, track_scores, features)]
1.detections List的第一个元素中有for，後面带有bbox,score，
不晓得这是什麽意思@@?
实际在跑侦错模式时，此行程式码会进入数次。这个for
2.第二个元素中.. feature in这是什麽意思呢?
谢谢。
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1F：→ crazycy: 关键字：list comprehension 05/02 02:11
2F：→ crazycy: for bbox,score, feature in zip(detections, track_s... 05/02 02:12
3F：→ crazycy: detections.append(Detection(bbox, score, feature) 05/02 02:12
4F：→ crazycy: 有点像以上的code 05/02 02:12
5F：→ james999: 谢谢crazycy大，完全看懂了^^ 05/02 02:30
另有一个问题想请问，某段程式呼叫了_match函式，追踪到_match後，
发现里面又定义了一个函式，而这些函式参数完全不晓得是哪里来的@@
_match只有detections这个引数阿...
再麻烦板友解惑，谢谢了..
def _match(self, detections):
def gated_metric(tracks, dets, track_indices, detection_indices):
features = np.array([dets[i].feature for i in detection_indices])
targets = np.array([tracks[i].track_id for i in track_indices])
cost_matrix = self.metric.distance(features, targets)
cost_matrix = linear_assignment.gate_cost_matrix(
self.kf, cost_matrix, tracks, dets, track_indices,
detection_indices)
return cost_matrix
# Split track set into confirmed and unconfirmed tracks.
confirmed_tracks = [
i for i, t in enumerate(self.tracks) if t.is_confirmed()]
unconfirmed_tracks = [
i for i, t in enumerate(self.tracks) if not t.is_confirmed()]
※ 编辑: james999 (36.230.200.240), 05/02/2019 02:33:36
6F：推 art1: 要去看 linear_assignment.py 05/02 02:57
7F：→ james999: 谢谢art1大 :) 05/02 16:21