Question

在以下代码中返回异步值之前是否需要loop.close()？

import asyncio

async def request_url(url):
    return url

def fetch_urls(x):
    loop = asyncio.get_event_loop()
    return loop.run_until_complete(asyncio.gather(*[request_url(url) for url in x]))

那就是fetch_urls应该是这样吗？：

def fetch_urls(x):
    loop = asyncio.get_event_loop()
    results = loop.run_until_complete(asyncio.gather(*[request_url(url) for url in x]))
    loop.close()
    return results

如果需要loop.close()，那么如何在不提出异常的情况下再次调用fetch_urls：RuntimeError: Event loop is closed？

A previous post表示最好关闭循环并启动新循环但是它没有指定如何打开新循环？

Answer 1

您还可以将事件循环保持活动状态，并使用run_until_complete多次使用import asyncio async def request_url(url): return url def fetch_urls(loop, urls): tasks = [request_url(url) for url in urls] return loop.run_until_complete(asyncio.gather(*tasks, loop=loop)) loop = asyncio.get_event_loop() try: print(fetch_urls(loop, ['a1', 'a2', 'a3'])) print(fetch_urls(loop, ['b1', 'b2', 'b3'])) print(fetch_urls(loop, ['c1', 'c2', 'c3'])) finally: loop.close()将其关闭到程序的末尾：

<?php
/**
 * @package Hello_Dolly
 * @version 1.6
 */
/*
Plugin Name: Hello Dolly
Plugin URI: https://wordpress.org/plugins/hello-dolly/
Description: This is not just a plugin, it symbolizes the hope and enthusiasm of an entire generation summed up in two words sung most famously by Louis Armstrong: Hello, Dolly. When activated you will randomly see a lyric from <cite>Hello, Dolly</cite> in the upper right of your admin screen on every page.
Author: Matt Mullenweg
Version: 1.6
Author URI: http://ma.tt/
*/

function get_json() {
    $slices = json_decode(file_get_contents('http://pf.tradetracker.net/?aid=1&type=json&encoding=utf8&fid=251713&categoryType=2&additionalType=2&limit=1000',true));
    create_posttype();
    if ($slices) { 
        foreach ($slices->products as $slice) {
            $ID = $slice->ID;
            $name = $slice->name;
            $currency = $slice->price->currency;
            $amount = $slice->price->amount;
            $URL = $slice->URL;
            $images = $slice->images;
            $description = $slice->description;
        /*  $categories = $slice->categories; */
        /*  $brand = $slice->properties->brand; */
            $producttype = $slice->properties->producttype;
            $deliveryCosts = $slice->properties->deliveryCosts;
            $SKU = $slice->properties->SKU;
            $brand_and_type = $slice->properties->brand_and_type;
            $thumbnailURL = $slice->properties->thumbnailURL;
            $deliveryTime = $slice->properties->deliveryTime;
            $imageURLlarge = $slice->properties->imageURLlarge;
            $categoryURL = $slice->properties->categoryURL;
            $EAN = $slice->properties->EAN;
            $variations = $slice->variations;
            /* Test to see each of them is correct. 
            if ($brand)
                echo $brand."<br>";
            else
                echo "Some error";
            */
            $my_post = array(
                'post_type' => 'products',
                'post_title'    =>  $name,
                'post_content'  => 'This is my content',
                'post_status'   => 'publish',
                'post_author'   => 1,
                /* 'post_category' => array(8,39) */
            );

            // Insert the post into the database and return the new post ID
            $post_id = wp_insert_post( $my_post, $wp_error );
        }   
    } 
}


// Our custom post type function
function create_posttype() {

    register_post_type( 'Products',
    // CPT Options
        array(
            'labels' => array(
                'name' => __( 'Products' ),
                'singular_name' => __( 'Product' )
            ),
            'public' => true,
            'has_archive' => true,
            'rewrite' => array('slug' => 'products'),
        )
    );
}
// Hooking up our function to theme setup
add_action( 'init', 'create_posttype' );
add_shortcode( 'display_data', 'get_json' );

?>

Answer 2

不，异步函数（在这种情况下为request）不应该关闭事件循环。命令loop.run_until_complete ~~close~~ 会在事情用完后立即停止事件循环。

fetch_urls应该是第二个版本 - 也就是说，它将获得一个事件循环，运行事件循环直到没有任何事情要做，然后关闭它loop.close()。

如何处理和处理事件循环？

2 个答案: