小编Kri*_* PC的帖子

我正在关注Swift.org的教程

以下switch语句示例引发错误.

let vegetable = "red pepper"
switch vegetable {
case "celery":
    print("Add some raisins and make ants on a log.")
case "cucumber", "watercress":
    print("That would make a good tea sandwich.")
case let x where x.hasSuffix("pepper"):
    print("Is it a spicy \(x)?")
default:
    print("Everything tastes good in soup.")
}

我得到的错误是: error: value of type 'String' has no member 'hasSuffix' case let x where x.hasSuffix("pepper"): 使用ubuntu 14.04和我的Swift版本swift --version Swift version 3.0 (swift-3.0-PREVIEW-2)

我正在尝试将https://github.com/axnsan12/drf-yasg这个库添加到我们的 django 应用程序并收到以下错误。

permission_classes=(permissions.AllowAny,),
  File "/env/lib/python3.7/site-packages/drf_yasg/views.py", line 67, in get_schema_view
    _generator_class = generator_class or swagger_settings.DEFAULT_GENERATOR_CLASS
  File "env/lib/python3.7/site-packages/drf_yasg/app_settings.py", line 122, in __getattr__
    val = perform_import(val, attr)
  File "env/lib/python3.7/site-packages/rest_framework/settings.py", line 166, in perform_import
    return import_from_string(val, setting_name)
  File "env/lib/python3.7/site-packages/rest_framework/settings.py", line 180, in import_from_string
    raise ImportError(msg)
ImportError: Could not import 'drf_yasg.generators.OpenAPISchemaGenerator' for API setting 'DEFAULT_GENERATOR_CLASS'. ImportError: cannot import name 'URLPattern' from 'rest_framework.compat' (env/lib/python3.7/site-packages/rest_framework/compat.py).

经过一番研究，我发现有些人建议安装这个包来解决这个问题

pip3 install packaging 

但这没有任何区别。任何其他好的 api 文档库可用于 django rest api？