TypeError：“ str”对象不可调用

Question

我在程序中添加了几行代码，以使用BeautifulSoup将html转换为json，但是对于这些添加的代码行却出现了错误。

import httplib, urllib
from bs4 import BeautifulSoup
import json

params = urllib.urlencode({'cmm': 'onion', 'mkt': '', 'search': ''})
headers = {'Cookie': 'ASPSESSIONIDCCRBQBBS=KKLPJPKCHLACHBKKJONGLPHE; ASP.NET_SessionId=kvxhkhqmjnauyz55ult4hx55; ASPSESSIONIDAASBRBAS=IEJPJLHDEKFKAMOENFOAPNIM','Origin': 'http://agmarknet.nic.in', 'Accept-Encoding': 'gzip, deflate', 'Accept-Language': 'en-GB,en-US;q=0.8,en;q=0.6','Upgrade-Insecure-Requests': '1','User-Agent': 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.93 Safari/537.36', 'Content-Type': 'application/x-www-form-urlencoded','Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8', 'Cache-Control': 'max-age=0','Referer': 'http://agmarknet.nic.in/mark2_new.asp','Connection': 'keep-alive'}
conn = httplib.HTTPConnection("agmarknet.nic.in")
conn.request("POST", "/SearchCmmMkt.asp", params, headers)
response = conn.getresponse()
print response.status, response.reason
data = response.read()
htmldata = [[cell.text for cell in row("td")]for row in BeautifulSoup((data)("tr"),"lxml")]
x = json.dumps(dict(htmldata))
print x

我收到一个错误

Traceback (most recent call last):
  File "commodity.py", line 12, in <module>
    data1 = [[cell.text for cell in row("td")]for row in BeautifulSoup((data)("tr"),"lxml")]
TypeError: 'str' object is not callable`enter code here`

在运行代码。 谁能告诉我解决此错误的正确方法。

Answer 1

您正在尝试在此处“调用”字符串：

BeautifulSoup((data)("tr"),"lxml")

(data)是一个字符串，而(data)("tr")是对该字符串的调用。

也许您想查找所有<tr>元素：

BeautifulSoup(data, "lxml").find_all("tr")

发表完整的声明：

htmldata = [[cell.text for cell in row("td")] for row in BeautifulSoup(data, "lxml").find_all("tr")]