小编ken*_*way的帖子

任何人都可以解释为什么loc在python pandas中使用的例子如下所示？

for i in range(0, 2):
  for j in range(0, 3):
    df.loc[(df.Age.isnull()) & (df.Gender == i) & (df.Pclass == j+1),
            'AgeFill'] = median_ages[i,j]

我正在寻找一个区分C++ cerr和coutC++ 的例子？

我什么时候需要使用cerr？

from bs4 import BeautifulSoup
import requests
from requests.auth import HTTPProxyAuth

url = "http://www.transtats.bts.gov/Data_Elements.aspx?Data=2" 
proxies = {"http":"xxx.xxx.x.xxx: port"}
auth = HTTPProxyAuth("username", "password")
r = requests.get(url, proxies=proxies, auth=auth)
soup = BeautifulSoup(r.text,"html.parser") 
viewstate_element = soup.find(id = "__VIEWSTATE").attrs 
viewstate = viewstate_element["value"]
eventvalidation_element = soup.find(id="__EVENTVALIDATION").attrs
eventvalidation = eventvalidation_element["value"]


data =     {'AirportList':"BOS",'CarrierList':"VX",'Submit':'Submit',"__EVENTTARGET":"","__EVENTARGUMENT":"","__EVENTVALIDATION":eventvalidation,"}
r = requests.post(url, proxies, auth, data )
print r

这个代码在我使用时工作正常requests.get(url, proxies=proxies, auth=auth),但是当有一些数据必须通过requests.post()代理身份验证发送时该怎么办？