我用这段代码测试了它：
from gevent import wsgi, monkey; monkey.patch_all()
from flask import Flask, url_for
app = Flask(__name__)
@app.route('/<int:n>')
def index(n):
for i in xrange(n):
url = url_for('index', n=i)
return url
wsgi.WSGIServer(('', 8000), app).serve_forever()
结果：
/1 Requests per second: 2721.94 [#/sec] (mean)/10 Requests per second: 1080.16 [#/sec] (mean)/100 Requests per second: 144.66 [#/sec] (mean)确实有点慢。
好消息是时间复杂度是线性的，O(1).
下面是 cProfile 转储
如果我是烧瓶开发人员，我会看看为什么 url_for 调用urljoin和urlsplit. 如果我正确理解了 werkzeug 代码，它会对生成的 url 执行验证。
13726316 function calls (13526316 primitive calls) in 16.918 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
400000 0.272 0.000 0.453 0.000 <string>:8(__new__)
100000 0.120 0.000 0.140 0.000 app.py:1484(inject_url_defaults)
200000 0.762 0.000 1.052 0.000 datastructures.py:316(__init__)
100000 0.132 0.000 0.395 0.000 globals.py:16(_lookup_object)
100000 0.913 0.000 16.996 0.000 helpers.py:250(url_for)
300000 0.527 0.000 0.846 0.000 local.py:156(top)
100000 0.136 0.000 0.645 0.000 local.py:289(_get_current_object)
100000 0.112 0.000 0.901 0.000 local.py:333(__getattr__)
300000 0.264 0.000 0.320 0.000 local.py:66(__getattr__)
200000 0.059 0.000 0.059 0.000 routing.py:1199(update)
200000 0.147 0.000 0.147 0.000 routing.py:1455(get_host)
400000/200000 0.802 0.000 6.297 0.000 routing.py:1520(_partial_build)
200000 1.791 0.000 14.382 0.000 routing.py:1541(build)
400000 0.153 0.000 0.153 0.000 routing.py:1601(<genexpr>)
200000 1.830 0.000 5.181 0.000 routing.py:701(build)
200000 0.275 0.000 0.275 0.000 routing.py:743(suitable_for)
200000 0.256 0.000 0.256 0.000 routing.py:928(to_url)
400000 0.935 0.000 2.816 0.000 urlparse.py:128(urlparse)
400000 1.010 0.000 1.428 0.000 urlparse.py:159(urlsplit)
200000 0.175 0.000 0.274 0.000 urlparse.py:214(urlunparse)
200000 0.099 0.000 0.099 0.000 urlparse.py:224(urlunsplit)
200000 1.961 0.000 5.637 0.000 urlparse.py:242(urljoin)
5263 0.004 0.000 0.019 0.000 urlparse.py:62(clear_cache)
400000 0.483 0.000 0.783 0.000 urls.py:36(_quote)
400000 0.509 0.000 1.534 0.000 urls.py:369(url_quote)
100000 0.068 0.000 0.068 0.000 wrappers.py:85(blueprint)
505263 0.235 0.000 0.235 0.000 {built-in method __new__ of type object at 0x10d044248}
200000 0.101 0.000 0.169 0.000 {getattr}
100000 0.114 0.000 0.114 0.000 {hasattr}
2000000 0.642 0.000 0.642 0.000 {isinstance}
505263 0.073 0.000 0.073 0.000 {len}
200000 0.041 0.000 0.041 0.000 {method 'add' of 'set' objects}
600000 0.127 0.000 0.127 0.000 {method 'append' of 'list' objects}
5263 0.015 0.000 0.015 0.000 {method 'clear' of 'dict' objects}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
5263 0.003 0.000 0.003 0.000 {method 'find' of 'str' objects}
100000 0.072 0.000 0.072 0.000 {method 'find' of 'unicode' objects}
700000 0.231 0.000 0.231 0.000 {method 'get' of 'dict' objects}
400000 0.105 0.000 0.105 0.000 {method 'iteritems' of 'dict' objects}
200000 0.116 0.000 0.116 0.000 {method 'join' of 'str' objects}
200000 0.157 0.000 0.157 0.000 {method 'join' of 'unicode' objects}
200000 0.134 0.000 0.134 0.000 {method 'lstrip' of 'unicode' objects}
300000 0.052 0.000 0.052 0.000 {method 'pop' of 'dict' objects}
200000 0.079 0.000 0.079 0.000 {method 'remove' of 'list' objects}
400000 0.249 0.000 0.249 0.000 {method 'rstrip' of 'str' objects}
200000 0.183 0.000 0.183 0.000 {method 'split' of 'str' objects}
400000 0.339 0.000 0.339 0.000 {method 'split' of 'unicode' objects}
300000 0.056 0.000 0.056 0.000 {thread.get_ident}
我有2-3个实用的解决方案给你：
如果您有带有数字 id 的 RESTful API，最后一个选项可能如下所示：
datum_url_template = url_for("datum", n=999)
def url_for_datum(n):
return datum_url_template.replace("999", str(n))
foobar_url_template = url_for("foobar", n=777)
def url_for_foobar(n):
return foobar_url_template.replace("777", str(n))