使用 lxml 解析 XML 的问题

Question

我一直在尝试将 XML 提要解析为 Pandas 数据框，但不知道哪里出错了。

import pandas as pd
import requests
import lxml.objectify
path = "http://www2.cineworld.co.uk/syndication/listings.xml"

xml = lxml.objectify.parse(path)
root = xml.getroot()

下一段代码是解析我想要的位并创建一个显示字典列表。

shows_list = []
for r in root.cinema:
    rec = {}
    rec['name'] = r.attrib['name']
    rec['info'] = r.attrib["root"] + r.attrib['url']
    listing = r.find("listing")
    for f in listing.film:
        film = rec
        film['title'] = f.attrib['title']
        film['rating'] = f.attrib['rating']
        shows = f.find("shows")
        for s in shows['show']:
            show = rec
            show['time'] = s.attrib['time']
            show['url'] = s.attrib['url']
            #print show
            shows_list.append(rec)

df = pd.DataFrame(show_list)

当我运行代码时，电影和时间字段似乎在行内被复制了多次。但是，如果我在代码中添加一个 print 语句（它被注释掉了），那么字典看起来就像我所期望的那样。

我做错了什么？请随时让我知道是否有更 Pythonic 的方式来执行解析过程。

编辑：澄清：

如果我使用打印语句检查循环时发生的情况，这些是最后五行数据。

{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'TBC', 'name': 'Cineworld Stoke-on-Trent', 'title': "Dad's Army", 'url': '/booking?performance=4729365&seats=STANDARD', 'time': '2016-02-07T20:45:00'}
{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'TBC', 'name': 'Cineworld Stoke-on-Trent', 'title': "Dad's Army", 'url': '/booking?performance=4729366&seats=STANDARD', 'time': '2016-02-08T20:45:00'}
{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'TBC', 'name': 'Cineworld Stoke-on-Trent', 'title': "Dad's Army", 'url': '/booking?performance=4729367&seats=STANDARD', 'time': '2016-02-09T20:45:00'}
{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'TBC', 'name': 'Cineworld Stoke-on-Trent', 'title': "Dad's Army", 'url': '/booking?performance=4729368&seats=STANDARD', 'time': '2016-02-10T20:45:00'}
{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'TBC', 'name': 'Cineworld Stoke-on-Trent', 'title': "Dad's Army", 'url': '/booking?performance=4729369&seats=STANDARD', 'time': '2016-02-11T20:45:00'}
{'info': 'http://cineworld.co.uk/cinemas/107/information', 'rating': 'PG', 'name': 'Cineworld Stoke-on-Trent', 'title': 'Autism Friendly Screening - Goosebumps', 'url': '/booking?performance=4782937&seats=STANDARD', 'time': '2016-02-07T11:00:00'}

这是列表的结尾： ...

{'info': 'http://cineworld.co.uk/cinemas/107/information',
  'name': 'Cineworld Stoke-on-Trent',
  'rating': 'PG',
  'time': '2016-02-07T11:00:00',
  'title': 'Autism Friendly Screening - Goosebumps',
  'url': '/booking?performance=4782937&seats=STANDARD'},
 {'info': 'http://cineworld.co.uk/cinemas/107/information',
  'name': 'Cineworld Stoke-on-Trent',
  'rating': 'PG',
  'time': '2016-02-07T11:00:00',
  'title': 'Autism Friendly Screening - Goosebumps',
  'url': '/booking?performance=4782937&seats=STANDARD'},
 {'info': 'http://cineworld.co.uk/cinemas/107/information',
  'name': 'Cineworld Stoke-on-Trent',
  'rating': 'PG',
  'time': '2016-02-07T11:00:00',
  'title': 'Autism Friendly Screening - Goosebumps',
  'url': '/booking?performance=4782937&seats=STANDARD'},
 {'info': 'http://cineworld.co.uk/cinemas/107/information',
  'name': 'Cineworld Stoke-on-Trent',
  'rating': 'PG',
  'time': '2016-02-07T11:00:00',
  'title': 'Autism Friendly Screening - Goosebumps',
  'url': '/booking?performance=4782937&seats=STANDARD'}]

Answer 1

您的代码只有一个不断更新的对象：rec。试试这个：

from copy import copy
shows_list = []
for r in root.cinema:
    rec = {}
    rec['name'] = r.attrib['name']
    rec['info'] = r.attrib["root"] + r.attrib['url']
    listing = r.find("listing")
    for f in listing.film:
        film = copy(rec) # New object
        film['title'] = f.attrib['title']
        film['rating'] = f.attrib['rating']
        shows = f.find("shows")
        for s in shows['show']:
            show = copy(film) # New object, changed reference
            show['time'] = s.attrib['time']
            show['url'] = s.attrib['url']
            #print show
            shows_list.append(show) # Changed reference

df = pd.DataFrame(show_list)

通过这种结构，rec中的数据被复制到每个film中，每个film中的数据被复制到每个show中。然后，最后将show 添加到shows_list。

您可能想阅读this article 以了解更多关于film = rec 行中发生的事情，即您正在为原始字典指定另一个名称，而不是创建一个新字典。