Django Urls如何配置可选查询参数以支持无season参数的请求

1. 调整urls.py配置（二选一即可） #

方案1：注册两条路由指向同一视图 #

直接注册带season参数和不带season参数的两条规则，都匹配同一个视图类：

app_name = 'main'
urlpatterns = [    
    path('',include(router.urls)), 
    # 带season参数的路由
    path('player_id=<str:player>%season_id=<str:season>',views.MatchesList.as_view()),
    # 不带season参数的路由
    path('player_id=<str:player>',views.MatchesList.as_view())
]

方案2：用re_path配置可选参数正则 #

如果不想写重复路由，可以用正则路由将season部分标记为可选：

from django.urls import re_path

app_name = 'main'
urlpatterns = [    
    path('',include(router.urls)), 
    re_path(r'^player_id=(?P<player>[^%]+)(%season_id=(?P<season>[^%]+))?$', views.MatchesList.as_view())
]

2. 调整views.py参数获取逻辑 #

不能直接从kwargs中强制取season参数，需要设置默认值为None，同时修正权限配置的语法问题（元组单个元素需要加逗号，否则不会被识别为权限集合）：

class MatchesList(generics.ListAPIView):
    serializer_class = MatchesSerializer
    permissions      = (IsAuthenticated,)

    def get_queryset(self):
        player = self.kwargs['player']
        # 从kwargs中取season，不存在则默认返回None
        season = self.kwargs.get('season', None)
        if season is None:
            queryset = Matches.objects.filter(player=player).all()
        else:      
            queryset = Matches.objects.filter(player=player,season=season).all()     
        return queryset

补充建议：实际开发中更推荐用查询参数（即?player_id=xxx&season_id=xxx的形式）传递这类筛选参数，不需要配置多路由，直接从self.request.query_params中取值即可，扩展性更强。

内容的提问来源于stack exchange，提问作者Tomas Garrido