小编use*_*006的帖子

我想让Flask Blueprint在执行任何路由之前始终运行一个方法.我没有用自定义装饰器装饰我的蓝图中的每个路线方法,而是希望能够做到这样的事情:

def my_method():
    do_stuff

section = Blueprint('section', __name__)

# Register my_method() as a setup method that runs before all routes
section.custom_setup_method(my_method())

@section.route('/two')
def route_one():
    do_stuff

@section.route('/one')
def route_two():
    do_stuff

然后,基本上都/section/one和/section/two运行my_method()在执行代码之前route_one()或route_two().

有没有办法做到这一点？

I seriously cannot think of a more basic use case of Union types than this:

test.js

// @flow
type Foo = {
  a: string,
  b: number
}

function func(o: Foo | string) {
  if (o instanceof Foo) {            // <<<<< ERROR
    console.log(o.a);
  } else {
    console.log(o);
  }
}

Flow gives me an error on the line:

o instanceof Foo

with this:

Cannot reference type Foo [1] from a value position.

What am I doing wrong and how do I make …

我正在尝试构建 Playground 应用程序以react-native-navigation使用此处的说明。一个简单的npm install失败，因为对等依赖项具有react: "*"和react-native: "*"，所以今天（2021 年 1 月）NPM 尝试安装react@17.0.1，但也尝试安装react-native@0.63.4，这需要react@16.13.1. 我收到以下错误：

npm ERR! While resolving: react-native-navigation@7.7.0
npm ERR! Found: react@17.0.1
npm ERR! node_modules/react
npm ERR!   peer react@"*" from the root project
...
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer react@"16.13.1" from react-native@0.63.4
npm ERR! node_modules/react-native
npm ERR!   peer react-native@"*" from the root project
npm ERR!   peer react-native@">=0.59" from @react-native-community/datetimepicker@2.6.2
npm …