[問題] Beautifulsoup find_all 找不到符合標籤
各位大大好：
小弟目前在學寫python+beautifulsoup+lxml
目前有個練習是讀取一份清單中的資料，來此資料再讀取、辨斷某個xml資料中是否有符合的tag存在：
比如xml中只有<centos>：
<centos>
<name>centos</name>
<version>7</version>
<download-url>http://ftp.ksu.edu.tw/pub/CentOS/7/isos/x86_64/CentOS-7-x86_64-DVD-1511.iso</download-url>
</centos>
並用下面的code讀取xml檔案後並嘗試判斷是否有找到或找不到對應的tag:
from bs4 import BeautifulSoup
soup = BeautifulSoup(open(os.xml))
os = "fedora"
for item in soup.findAll( os ):
print item.tag,item,attrib
if item == "":
print "OS %s not exist in DB"
else:
print "OS %s exist in DB"
看起來並不會執行，如果 os = "centos"，就能抓到對應的資料，但 os = "fedora"不行
求教：
1，如何判斷才是正確的方法？bs的網站說，findall在找不到tag時會return空字串，但我不太理解如何可以判斷空字串？看起來用 == ""是不行的。
2，另外執行python時會有下列錯誤，這個如何解決？
/usr/local/lib/python2.7/site-packages/bs4/__init__.py:166: UserWarning: No parser was explicitly specified, so I'm using the best available HTML parser for this system ("html.parser"). This usually isn't a problem, but if you run this code on another system, or in a different virtual environment, it may use a different parser and behave differently.
To get rid of this warning, change this:
BeautifulSoup([your markup])
to this:
BeautifulSoup([your markup], "html.parser")
markup_type=markup_type))
我有先爬過文，各種解決都不行，比如 BeautifulSoup(markup, "xml")
抱歉問的可能是很基本的問題，感謝指導：D
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 123.194.30.193
※ 文章網址: https://www.ptt.cc/bbs/Python/M.1462443807.A.61D.html
→
05/05 19:22, , 1F
05/05 19:22, 1F
→
05/05 19:24, , 2F
05/05 19:24, 2F
→
05/05 19:26, , 3F
05/05 19:26, 3F
→
05/05 23:57, , 4F
05/05 23:57, 4F
→
05/06 00:04, , 5F
05/06 00:04, 5F
→
05/06 00:05, , 6F
05/06 00:05, 6F
→
05/06 00:06, , 7F
05/06 00:06, 7F
→
05/06 00:06, , 8F
05/06 00:06, 8F
→
05/06 00:06, , 9F
05/06 00:06, 9F
Python 近期熱門文章
PTT數位生活區 即時熱門文章