Python-Requests,从字符串中提取url参数

Question

我正在使用这个令人敬畏的库requests来维护python 2和3兼容性并简化我的应用程序请求管理.

我有一个案例,我需要解析一个网址并替换其中一个参数.例如:

http://example.com?param1=a&token=TOKEN_TO_REPLACE&param2=c

我希望得到这个:

http://example.com?param1=a&token=NEW_TOKEN&param2=c

随着urllib我可以这样做:

from urllib.parse import urlparse
from urllib.parse import parse_qs
from urllib.parse import urlencode

url = 'http://example.com?param1=a&token=TOKEN_TO_REPLACE&param2=c'

o = urlparse(url)
query = parse_qs(o.query)
if query.get('token'):
    query['token'] = ['NEW_TOKEN', ]
    new_query = urlencode(query, doseq=True)
    url.split('?')[0] + '?' + new_query

>>> http://example.com?param2=c&param1=a&token=NEW_TOKEN

你如何使用requests图书馆实现同样的目标？

Answer 1

你不能用requests它; 如果为参数传递Python结构,则库会构建此类URL,但不提供任何解析它们的工具.这不是该项目的目标.

坚持urllib.parse解析参数的方法.获得字典或键值元组列表后,只需将其传递requests给再次构建URL:

try:
    # Python 3
    from urllib.parse import urlparse, parse_qs
except ImportError:
    # Python 2
    from urlparse import urlparse, parse_qs

o = urlparse(url)
query = parse_qs(o.query)
# extract the URL without query parameters
url = o._replace(query=None).geturl()

if 'token' in query:
    query['token'] = 'NEW_TOKEN'

requests.get(url, params=query)

你可以在Python 2和3中同时获得urlparse和parse_qs函数,如果你得到一个例外,你需要做的就是调整导入位置.

在Python 3上演示(没有导入异常保护)来演示已构建的URL:

>>> from urllib.parse import urlparse, parse_qs
>>> url = "http://httpbin.org/get?token=TOKEN_TO_REPLACE&param2=c"
>>> o = urlparse(url)
>>> query = parse_qs(o.query)
>>> url = o._replace(query=None).geturl()
>>> if 'token' in query:
...     query['token'] = 'NEW_TOKEN'
... 
>>> response = requests.get(url, params=query)
>>> print(response.text)
{
  "args": {
    "param2": "c", 
    "token": "NEW_TOKEN"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.5.1 CPython/3.4.2 Darwin/14.1.0"
  }, 
  "origin": "188.29.165.245", 
  "url": "http://httpbin.org/get?token=NEW_TOKEN&param2=c"
}

Answer 2

requests仅使用：

query = requests.utils.urlparse(url).query
params = dict(x.split('=') for x in query.split('&'))

if 'token' in params:
    params['token'] = 'NEW_TOKEN'

requests.get(url, params=params)