TypeError：“ str”對象不可調用

Question

我在程序中添加了幾行代碼，以使用BeautifulSoup將html轉換為json，但是對於這些添加的代碼行卻出現了錯誤。

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

我收到一個錯誤

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`

在運行代碼。 誰能告訴我解決此錯誤的正確方法。

Answer 1

您正在嘗試在此處“調用”字符串：

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

(data)是一個字符串，而(data)("tr")是對該字符串的調用。

也許您想查找所有<tr>元素：

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

發表完整的聲明：

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