如何使用python從網站抓取圖表？

Question

編輯：

所以我將下面的腳本代碼保存到一個文本文件中，但是使用re提取數據仍然不會返回任何信息。 我的代碼是：

file_object = open('source_test_script.txt', mode="r")
soup = BeautifulSoup(file_object, "html.parser")
pattern = re.compile(r"^var (chart[0-9]+) = new Highcharts.Chart\(({.*?})\);$", re.MULTILINE | re.DOTALL)
scripts = soup.find("script", text=pattern)
profile_text = pattern.search(scripts.text).group(1)
profile = json.loads(profile_text)

print profile["data"], profile["categories"]

---

我想從網站上提取圖表數據。 以下是圖表的源代碼。

  <script type="text/javascript">
    jQuery(function() {

    var chart1 = new Highcharts.Chart({

          chart: {
             renderTo: 'chart1',
              defaultSeriesType: 'column',
            borderWidth: 2
          },
          title: {
             text: 'Productions'
          },
          legend: {
            enabled: false
          },
          xAxis: [{
             categories: [1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016],

          }],
          yAxis: {
             min: 0,
             title: {
             text: 'Productions'
          }
          },

          series: [{
               name: 'Productions',
               data: [1,1,0,1,6,4,9,15,15,19,24,18,53,42,54,53,61,36]
               }]
       });
    });

    </script>

網站上有一些類似的圖表，稱為“ chart1”，“ chart2”等。我想提取以下數據：每個圖表的類別線和數據線：

categories: [1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016]

data: [1,1,0,1,6,4,9,15,15,19,24,18,53,42,54,53,61,36]

Answer 1

另一種方法是像在控制台中一樣使用Highcharts的JavaScript庫，並使用Selenium來拉取它。

import time
from selenium import webdriver

website = ""

driver = webdriver.Firefox()
driver.get(website)
time.sleep(5)

temp = driver.execute_script('return window.Highcharts.charts[0]'
                             '.series[0].options.data')
data = [item[1] for item in temp]
print(data)

根據要嘗試繪制圖表的系列和圖表，可能會略有不同。

Answer 2

我會結合使用正則表達式和yaml解析器。 下面又快又臟-您可能需要對正則表達式進行tweek，但是它可以與示例一起使用：

import re
import sys
import yaml

chart_matcher = re.compile(r'^var (chart[0-9]+) = new Highcharts.Chart\(({.*?})\);$',
        re.MULTILINE | re.DOTALL)

script = sys.stdin.read()

m = chart_matcher.findall(script)

for name, data in m:
    print name
    try:
        chart = yaml.safe_load(data)
        print "categories:", chart['xAxis'][0]['categories']
        print "data:", chart['series'][0]['data']
    except Exception, e:
        print e

需要yaml庫（ pip install PyYAML ），在將其傳遞給正則表達式之前，應使用BeautifulSoup提取正確的<script>標記。

編輯 -完整示例

對不起，我沒有說清楚。 您使用BeautifulSoup解析HTML並提取<script>元素，然后使用PyYAML解析javascript對象聲明。 您不能使用內置的json庫，因為它不是有效的JSON，但是普通的javascript對象聲明（即，沒有函數）是YAML的子集。

from bs4 import BeautifulSoup
import yaml
import re

file_object = open('source_test_script.txt', mode="r")
soup = BeautifulSoup(file_object, "html.parser")

pattern = re.compile(r"var (chart[0-9]+) = new Highcharts.Chart\(({.*?})\);", re.MULTILINE | re.DOTALL | re.UNICODE)

charts = {}

# find every <script> tag in the source using beautifulsoup
for tag in soup.find_all('script'):

    # tabs are special in yaml so remove them first
    script = tag.text.replace('\t', '')

    # find each object declaration
    for name, obj_declaration in pattern.findall(script):
        try:
            # parse the javascript declaration
            charts[name] = yaml.safe_load(obj_declaration)
        except Exception, e:
            print "Failed to parse {0}: {1}".format(name, e)

# extract the data you want
for name in charts:
    print "## {0} ##".format(name);
    print "categories:", charts[name]['xAxis'][0]['categories']
    print "data:", charts[name]['series'][0]['data']
    print

輸出：

## chart1 ##
categories: [1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016]
data: [22, 1, 0, 1, 6, 4, 9, 15, 15, 19, 24, 18, 53, 42, 54, 53, 61, 36]

請注意，我不得不對正則表達式進行周處理，以使其處理BeautifulSoup的unicode輸出和空格-在我的原始示例中，我只是將您的源直接通過管道傳遞給了正則表達式。

編輯2-沒有Yaml

鑒於javascript看起來是部分生成的，因此您可以期望的最好成績是搶占先機-雖然不太雅致，但可能會對您有用。

from bs4 import BeautifulSoup
import json
import re

file_object = open('citec.repec.org_p_c_pcl20.html', mode="r")
soup = BeautifulSoup(file_object, "html.parser")

pattern = re.compile(r"var (chart[0-9]+) = new Highcharts.Chart\(({.*?})\);", re.MULTILINE | re.DOTALL | re.UNICODE)

charts = {}

for tag in soup.find_all('script'):

    # tabs are special in yaml so remove them first
    script = tag.text

    values = {}

    # find each object declaration
    for name, obj_declaration in pattern.findall(script):
        for line in obj_declaration.split('\n'):
            line = line.strip('\t\n ,;')
            for field in ('data', 'categories'):
                if line.startswith(field + ":"):
                    data = line[len(field)+1:]
                    try:
                        values[field] = json.loads(data)
                    except:
                        print "Failed to parse %r for %s" % (data, name)

        charts[name] = values

print charts

請注意，它對於chart7失敗，因為它引用了另一個變量。