blocks|key|2736657|text|使用PyV8，我可以做到这一点。但是，我必须用return替换document.write，因为没有DOM，因此也就没有document。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2736658|import+PyV8
ctx+=+PyV8.JSContext()
ctx.enter()

js+=+"""
function+escramble_758(){
var+a,b,c
a='%2B1+'
b='84-'
a%2B='425-'
b%2B='7450'
c='9'
document.write(a%2Bc%2Bb)
}
escramble_758()
"""

print+ctx.eval(js.replace("document.write",+"return+"))|code-block|syntax|javascript|2736659|或者，您可以创建一个模拟文档对象|2736660|class+MockDocument(object):

++++def+__init__(self):
++++++++self.value+=+''

++++def+write(self,+*args):
++++++++self.value+%2B=+''.join(str(i)+for+i+in+args)


class+Global(PyV8.JSClass):
++++def+__init__(self):
++++++++self.document+=+MockDocument()

scope+=+Global()
ctx+=+PyV8.JSContext(scope)
ctx.enter()
ctx.eval(js)
print+scope.document.value|2736661|entityMap|0|LINK|mutability|MUTABLE|url|https://code.google.com/p/pyv8/^0|N|6|V|E|1O|8|2|4|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|17|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|18|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|19|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

Using <a href="https://code.google.com/p/pyv8/" rel="noreferrer">PyV8</a>, I can do this. However, I have to replace <code>document.write</code> with <code>return</code> because there's no DOM and therefore no <code>document</code>.

<pre><code>import PyV8
ctx = PyV8.JSContext()
ctx.enter()

js = """
function escramble_758(){
var a,b,c
a='+1 '
b='84-'
a+='425-'
b+='7450'
c='9'
document.write(a+c+b)
}
escramble_758()
"""

print ctx.eval(js.replace("document.write", "return "))
</code></pre>

Or you could create a mock document object

<pre><code>class MockDocument(object):

 def __init__(self):
 self.value = ''

 def write(self, *args):
 self.value += ''.join(str(i) for i in args)


class Global(PyV8.JSClass):
 def __init__(self):
 self.document = MockDocument()

scope = Global()
ctx = PyV8.JSContext(scope)
ctx.enter()
ctx.eval(js)
print scope.document.value
</code></pre>

blocks|key|2526912|text|您也可以使用Js2Py，它是用纯python编写的，可以执行javascript并将其转换为python。支持几乎整个JavaScript，甚至标签、getters、setters和其他很少使用的特性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2526913|import+js2py

js+=+"""
function+escramble_758(){
var+a,b,c
a='%2B1+'
b='84-'
a%2B='425-'
b%2B='7450'
c='9'
document.write(a%2Bc%2Bb)
}
escramble_758()
""".replace("document.write",+"return+")

result+=+js2py.eval_js(js)++#+executing+JavaScript+and+converting+the+result+to+python+string+|code-block|syntax|javascript|2526914|Js2Py的优点包括可移植性和非常容易与python集成(因为基本上JavaScript正在被转换为python)。|2526915|要安装：|2526916|pip+install+js2py|2526917|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

You can also use Js2Py which is written in pure python and is able to both execute and translate javascript to python. Supports virtually whole JavaScript even labels, getters, setters and other rarely used features. 

<pre><code>import js2py

js = """
function escramble_758(){
var a,b,c
a='+1 '
b='84-'
a+='425-'
b+='7450'
c='9'
document.write(a+c+b)
}
escramble_758()
""".replace("document.write", "return ")

result = js2py.eval_js(js) # executing JavaScript and converting the result to python string 
</code></pre>

Advantages of Js2Py include portability and extremely easy integration with python (since basically JavaScript is being translated to python). 

To install:

<pre><code>pip install js2py
</code></pre>

blocks|key|2736734|text|另一个解决方案是PyV8似乎没有得到维护，并且依赖于旧版本的libv8。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2736735|PyMiniRacer它是一个围绕v8引擎的包装器，它可以与新版本一起工作，并得到积极维护。|offset|length|2736736|pip+install+py-mini-racer|style|CODE|2736737|from+py_mini_racer+import+py_mini_racer
ctx+=+py_mini_racer.MiniRacer()
ctx.eval("""
function+escramble_758(){
++++var+a,b,c
++++a='%2B1+'
++++b='84-'
++++a%2B='425-'
++++b%2B='7450'
++++c='9'
++++return+a%2Bc%2Bb;
}
""")
ctx.call("escramble_758")|code-block|syntax|javascript|2736738|是的，您必须按照其他人的建议用return替换document.write|2736739|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/sqreen/PyMiniRacer^0|0|0|B|0|0|0|P|0|0|F|6|N|E|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@$D|10|E|11|1|12]]|A|$]]|$1|F|3|G|5|6|7|13|8|@$D|14|E|15|H|I]]|9|@]|A|$]]|$1|J|3|K|5|L|7|16|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|17|8|@$D|18|E|19|H|I]|$D|1A|E|1B|H|I]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

One more solution as PyV8 seems to be unmaintained and dependent on the old version of libv8. 

<a href="https://github.com/sqreen/PyMiniRacer" rel="noreferrer">PyMiniRacer</a> It's a wrapper around the v8 engine and it works with the new version and is actively maintained.

<code>pip install py-mini-racer</code>

<pre><code>from py_mini_racer import py_mini_racer
ctx = py_mini_racer.MiniRacer()
ctx.eval("""
function escramble_758(){
 var a,b,c
 a='+1 '
 b='84-'
 a+='425-'
 b+='7450'
 c='9'
 return a+c+b;
}
""")
ctx.call("escramble_758")
</code></pre>

And yes, you have to replace <code>document.write</code> with <code>return</code> as others suggested

blocks|key|47894|text|您可以使用js2py上下文来执行您的js代码，并使用模拟文档对象从document.write获得输出：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|47895|import+js2py

js+=+"""
var+output;
document+=+{
++++write:+function(value){
++++++++output+=+value;
++++}
}
"""+%2B+your_script

context+=+js2py.EvalJs()
context.execute(js)
print(context.output)|code-block|syntax|javascript|47896|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can use js2py context to execute your js code and get output from document.write with mock document object:

<pre><code>import js2py

js = """
var output;
document = {
 write: function(value){
 output = value;
 }
}
""" + your_script

context = js2py.EvalJs()
context.execute(js)
print(context.output)
</code></pre>

blocks|key|2527090|text|在quickjs问世之后，quickjs应该是最好的选择。只要pip+install+quickjs，你就可以开始工作了。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2527091|根据自述文件中的示例进行修改。|2527092|from+quickjs+import+Function

js+=+"""
function+escramble_758(){
var+a,b,c
a='%2B1+'
b='84-'
a%2B='425-'
b%2B='7450'
c='9'
document.write(a%2Bc%2Bb)
escramble_758()
}
"""

escramble_758+=+Function('escramble_758',+js.replace("document.write",+"return+"))

print(escramble_758())|code-block|syntax|javascript|2527093|https://github.com/PetterS/quickjs|2527094|entityMap|0|LINK|mutability|MUTABLE|url^0|V|J|0|0|0|0|Y|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Y|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Z|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|10|8|@]|D|@$9|11|A|12|1|13]]|E|$]]|$1|O|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|N]]]]

quickjs should be the best option after quickjs come out. Just <code>pip install quickjs</code> and you are ready to go.

modify based on the example on README.

<pre><code>from quickjs import Function

js = """
function escramble_758(){
var a,b,c
a='+1 '
b='84-'
a+='425-'
b+='7450'
c='9'
document.write(a+c+b)
escramble_758()
}
"""

escramble_758 = Function('escramble_758', js.replace("document.write", "return "))

print(escramble_758())
</code></pre>

<a href="https://github.com/PetterS/quickjs" rel="nofollow noreferrer">https://github.com/PetterS/quickjs</a>

blocks|key|2736798|text|您可以使用requests-html，它将下载并使用下面的铬。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2736799|from+requests_html+import+HTML

html+=+HTML(html="<a+href='http://www.example.com/'>")

script+=+"""
function+escramble_758(){
++++var+a,b,c
++++a='%2B1+'
++++b='84-'
++++a%2B='425-'
++++b%2B='7450'
++++c='9'
++++return+a%2Bc%2Bb;
}
"""

val+=+html.render(script=script,+reload=False)
print(val)
#+%2B1+425-984-7450|code-block|syntax|javascript|2736800|有关此阅读here的更多信息|2736801|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/psf/requests-html|1|https://requests-html.kennethreitz.org/#using-without-requests^0|5|D|0|0|0|5|4|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|K|3|-4|5|6|7|13|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]]]

You can use <a href="https://github.com/psf/requests-html" rel="nofollow noreferrer">requests-html</a> which will download and use chromium underneath.

<pre class="lang-py prettyprint-override"><code>from requests_html import HTML

html = HTML(html="&lt;a href='http://www.example.com/'&gt;")

script = """
function escramble_758(){
 var a,b,c
 a='+1 '
 b='84-'
 a+='425-'
 b+='7450'
 c='9'
 return a+c+b;
}
"""

val = html.render(script=script, reload=False)
print(val)
# +1 425-984-7450
</code></pre>

More on this read <a href="https://requests-html.kennethreitz.org/#using-without-requests" rel="nofollow noreferrer">here</a>

I have HTML webpages that I am crawling using xpath. The <code>etree.tostring</code> of a certain node gives me this string:

<pre><code>&lt;script&gt;
&lt;!--
function escramble_758(){
 var a,b,c
 a='+1 '
 b='84-'
 a+='425-'
 b+='7450'
 c='9'
 document.write(a+c+b)
}
escramble_758()
//--&gt;
&lt;/script&gt;
</code></pre>

I just need the output of <code>escramble_758()</code>. I can write a regex to figure out the whole thing, but I want my code to remain tidy. What is the best alternative?

I am zipping through the following libraries, but I didnt see an exact solution. Most of them are trying to emulate browser, making things snail slow.

<ul>
<li><a href="http://code.google.com/p/python-spidermonkey/">http://code.google.com/p/python-spidermonkey/</a> (clearly says <code>it's not yet possible to call a function defined in Javascript</code>)</li>
<li><a href="http://code.google.com/p/webscraping/">http://code.google.com/p/webscraping/</a> (don't see anything for Javascript, I may be wrong)</li>
<li><a href="http://pypi.python.org/pypi/selenium">http://pypi.python.org/pypi/selenium</a> (Emulating browser)</li>
</ul>

Edit: An example will be great.. (barebones will do)

Executing Javascript from Python

我有用xpath抓取的HTML网页。某个节点的etree.tostring给出了这个字符串：<script><!--function escramble_758(){ var a,b,c a='+1 ' b='84-' a+='425-' b+='7450' c='9' document.write(a+...

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