创建或附加到字典中的列表-可以缩短吗?

你可以用 defaultdict(list) .

from collections import defaultdict

result = defaultdict(list)
for widget_type, app in widgets:
    result[widget_type].append(app)

替代品 defaultdict setdefault 标准词典的方法:

 result = {}
 for widget_type, app in widgets:
     result.setdefault(widget_type, []).append(app)

可能有点慢但有效

result = {}
for widget_type, app in widgets:
    result[widget_type] = result.get(widget_type, []) + [app]