所以我有这个Python代码,我试图将其转换为node.js,但我不知道如何转换。
import urllib.request, re
def getDef(word):
link = "http://www.merriam-webster.com/dictionary/%s" % word
data = urllib.request.urlopen(link).read().decode()
try:
return re.search("<p>: (.*?)</p><p>", data).group(1)
except:
return "No match"
class newDefinition:
def __init__(self, word):
self.definition = getDef(word);
>>> definition = newDefintion("color")
>>> print(definition.definition)
a quality such as red, blue, green, yellow, etc., that you see when you look at something
在node.js中,尽管如此,我似乎可以像在python中一样返回它,因为它是回调方式做事,或者至少我似乎无法返回它,这就是为什么我问我该怎么做Node.js 等效还是它们没有等效?这是我到目前为止所做的,也许你可以发现我做错了什么以及如何解决它
var urllib = require("urllib"); // installed with npm
var getDef = function(word){
var link = "http://www.merriam-webster.com/dictionary/" + word;
var urlData = urllib.request(link, {}, function(err, data, res){
var re = new RegExp("<p>: (.*?)</p><p>");
var results = data.toString();
var match = re.exec(results)[1];
return match; // Expected it to give urlData the definition
});
return urlData;
}
var Definition = function(word){
this.definition = getDef(word);
}
definition = new Definition("color");
console.log(definition.definition); // this won't give the definition but the information of the urllib itself rather.
所以总的来说,试图弄清楚如何使用异步代码,这样我就可以返回我需要的东西,但我也不习惯这个概念,那么Python中是否有与此等效的东西?另外,如果您能为我指出一些关于异步代码的优秀文档,那就太好了。
最佳答案
由于 return
实际上只是退出函数而不是返回值,因此您需要使用回调。它看起来像这样:
var urllib = require("urllib");
var getDef = function(word, callback){
var link = 'http://www.merriam-webster.com/dictionary/' + word;
urllib.request(link, {}, function(err, data, res) {
var re = new RegExp('<p>: (.*?)</p><p>');
var results = data.toString();
var match = re.exec(results)[1];
callback(match);
});
};
然后您将在调用该函数时传递回调:
getDef('color', function(definition) {
console.log(definition);
});
<小时/>
编辑:设置对象的属性具有相同的想法。它可能看起来像这样:
var Definition = function(word) {
var self = this;
getDef(world, function(definition, callback) {
self.definition = definition;
callback.call(self);
});
};
并且会这样调用:
var definition = new Definition('color', function() {
console.log(definition.definition);
});
关于javascript - python 到 node.js 的混淆,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20557890/