使用 BeautifulSoup 提取相似的 XML 属性

Question

假设我有以下 XML：

<time from="2017-07-29T08:00:00" to="2017-07-29T09:00:00">
    <!-- Valid from 2017-07-29T08:00:00 to 2017-07-29T09:00:00 -->
    <symbol number="4" numberEx="4" name="Cloudy" var="04"/>
    <precipitation value="0"/>
    <!-- Valid at 2017-07-29T08:00:00 -->
    <windDirection deg="300.9" code="WNW" name="West-northwest"/>
    <windSpeed mps="1.3" name="Light air"/>
    <temperature unit="celsius" value="15"/>
    <pressure unit="hPa" value="1002.4"/>
</time>
<time from="2017-07-29T09:00:00" to="2017-07-29T10:00:00">
    <!-- Valid from 2017-07-29T09:00:00 to 2017-07-29T10:00:00 -->
    <symbol number="4" numberEx="4" name="Partly cloudy" var="04"/>
    <precipitation value="0"/>
    <!-- Valid at 2017-07-29T09:00:00 -->
    <windDirection deg="293.2" code="WNW" name="West-northwest"/>
    <windSpeed mps="0.8" name="Light air"/>
    <temperature unit="celsius" value="17"/>
    <pressure unit="hPa" value="1002.6"/>
</time>

我想从中收集time from、symbol name和temperature value，然后按以下方式打印出来：time from: symbol name, temperaure value——就像这样：2017-07-29, 08:00:00: Cloudy, 15°。

（如您所见，此 XML 中有几个 name 和 value 属性。）

到目前为止，我的方法非常简单：

#!/usr/bin/env python
# coding: utf-8

import re
from BeautifulSoup import BeautifulSoup

# data is set to the above XML
soup = BeautifulSoup(data)
# collect the tags of interest into lists. can it be done wiser?
time_l = []
symb_l = []
temp_l = []
for i in soup.findAll('time'):
    i_time = str(i.get('from'))
    time_l.append(i_time)
for i in soup.findAll('symbol'):
    i_symb = str(i.get('name'))
    symb_l.append(i_symb)
for i in soup.findAll('temperature'):
    i_temp = str(i.get('value'))
    temp_l.append(i_temp)
# join the forecast lists to a dict
forc_l = []
for i, j in zip(symb_l, temp_l):
    forc_l.append([i, j])
rez = dict(zip(time_l, forc_l))
# combine and format the rezult. can this dict be printed simpler?
wew = ''
for key in sorted(rez):
    wew += re.sub("T", ", ", key) + str(rez[key])
wew = re.sub("'", "", wew)
wew = re.sub("\[", ": ", wew)
wew = re.sub("\]", "°\n", wew)
# print the rezult
print wew

但我想一定有一些更好、更智能的方法？大多数情况下，我对从 XML 中收集属性感兴趣，实际上，我的方式对我来说似乎相当愚蠢。另外，有没有更简单的方法可以很好地打印出字典{'a': '[b, c]'}？

如果有任何提示或建议，将不胜感激。

Answer 1

from bs4 import BeautifulSoup
with open("sample.xml", "r") as f: # opening xml file
    content = f.read() # xml content stored in this variable
soup = BeautifulSoup(content, "lxml")
for values in soup.findAll("time"):
    print("{} : {}, {}°".format(values["from"], values.find("symbol")["name"], values.find("temperature")["value"]))

输出：

2017-07-29T08:00:00 : Cloudy, 15°
2017-07-29T09:00:00 : Partly cloudy, 17°

Answer 2

另外，你也可以通过导入xml.dom.minidom模块来获取xml数据。 这是您想要的数据：

from xml.dom.minidom import parse
doc = parse("path/to/xmlfile.xml") # parse an XML file by name
itemlist = doc.getElementsByTagName('time')
for items in itemlist:
    from_tag =  items.getAttribute('from')    
    symbol_list = items.getElementsByTagName('symbol') 
    symbol_name = [d.getAttribute('name') for d in symbol_list ][0] 
    temperature_list = items.getElementsByTagName('temperature') 
    temp_value = [d.getAttribute('value') for d in temperature_list ][0]
    print ("{} :  {}, {}°". format(from_tag, symbol_name, temp_value))

输出如下：

2017-07-29T08:00:00 :  Cloudy, 15°
2017-07-29T09:00:00 :  Partly cloudy, 17°

希望有用。

Answer 3

在这里您还可以使用内置模块的替代方式（我使用的是 python 3.6.2）：

import xml.etree.ElementTree as et # this is built-in module in python3
tree = et.parse("sample.xml")
root = tree.getroot()
for temp in root.iter("time"): # iterate time element in xml
    print(temp.attrib["from"], end=": ") # prints attribute of time element
    for sym in temp.iter("symbol"): # iterate symbol element within time element
        print(sym.attrib["name"], end=", ")
    for t in temp.iter("temperature"): # iterate temperature element within time element
        print(t.attrib["value"], end="°\n")