python - 如何抓取两个具有相同类名的表？

Question

这是我第一次抓取网站。问题是两个不同的表具有相同的类名。到目前为止，我已经了解到，要查找数据，我必须通过 HTML 标记的类名来查找它。 该代码可以从第一个表中抓取数据，但我也想对第二个表执行此操作。

import bs4 as bs
from urllib.request import Request, urlopen
import pandas as pd
from pyparsing import col


req = Request('https://www.worldometers.info/world-population/albania-population/',
              headers={'User-Agent': 'Mozilla/5.0'})

webpage = urlopen(req).read()

soup = bs.BeautifulSoup(webpage, 'html5lib')


# albania population
pupulation = soup.find(class_='col-md-8 country-pop-description')
for i in pupulation.find_all('strong')[1]:
    print()
    # print(i.text, end=" ")

# getting all city populattion
city_population = soup.find(
    class_='table table-hover table-condensed table-list')
# print(city_population.text, end=" ")


# the first table
# population of albania(historical)
df = pd.DataFrame(columns=['Year', 'Population' 'Yearly Change %', 'Yearly Change', 'Migrants (net)', 'Median Age', 'Fertility Rate',
                  'Density(P/Km2)', 'Urban Pop %', 'Urban Population', "Countrys Share of Population", 'World Population', 'Albania Global Rank'])

hisoric_population = soup.find('table',
                               class_='table table-striped table-bordered table-hover table-condensed table-list')


for row in hisoric_population.tbody.find_all('tr'):
    columns = row.find_all('td')

    if (columns != []):
        Year = columns[0].text.strip()
        Population = columns[1].text.strip()
        YearlyChange_percent = columns[2].text.strip('&0')
        YearlyChange = columns[3].text.strip()
        Migrants_net = columns[4].text.strip()
        MedianAge = columns[5].text.strip('&0')
        FertilityRate = columns[6].text.strip('&0')
        Density_P_Km2 = columns[7].text.strip()
        UrbanPop_percent = columns[8].text.strip('&0')
        Urban_Population = columns[9].text.strip()
        Countrys_Share_of_Population = columns[10].text.strip('&0')
        World_Population = columns[11].text.strip()
        Albania_Global_Rank = columns[12].text.strip()

        df = df.append({'Year': Year, 'Population': Population, 'Yearly Change %': YearlyChange_percent, 'Yearly Change': YearlyChange, 'Migrants (net)': Migrants_net, 'Median Age': MedianAge, 'Fertility Rate': FertilityRate,
                        'Density(P/Km2)': Density_P_Km2, 'Urban Pop %': UrbanPop_percent, 'Countrys Share of Population': Countrys_Share_of_Population, 'World Population': World_Population, 'Albania Global Rank': Albania_Global_Rank}, ignore_index=True)
df.head()
# print(df)

#the second table
# Albania Population Forecast

forecast_population = soup.find(
    'table', class_='table table-striped table-bordered table-hover table-condensed table-list')

for row in hisoric_population.tbody.find_all('tr'):
    columns = row.find_all('td')
    print(columns)

Answer 1

如上所述，使用.find_all()。当您使用 .find() 时，它只会返回找到的第一个实例。 find_all() 会将其找到的所有实例返回到列表中。然后，您需要通过索引值计算出您想要的具体索引。

另一方面，为什么不使用 pandas 来解析表格。它在底层使用了 BeautifulSoup。

import requests
import pandas as pd

url = 'https://www.worldometers.info/world-population/albania-population/'
response = requests.get(url)

dfs = pd.read_html(response.text, attrs={'class':'table table-striped table-bordered table-hover table-condensed table-list'})

historic_population = dfs[0]
forecast_population = dfs[1]

输出:

print(historic_population)
    Year  Population  ... World Population  AlbaniaGlobal Rank
0   2020     2877797  ...       7794798739                 140
1   2019     2880917  ...       7713468100                 140
2   2018     2882740  ...       7631091040                 140
3   2017     2884169  ...       7547858925                 140
4   2016     2886438  ...       7464022049                 141
5   2015     2890513  ...       7379797139                 141
6   2010     2948023  ...       6956823603                 138
7   2005     3086810  ...       6541907027                 134
8   2000     3129243  ...       6143493823                 131
9   1995     3112936  ...       5744212979                 130
10  1990     3286073  ...       5327231061                 125
11  1985     2969672  ...       4870921740                 125
12  1980     2682690  ...       4458003514                 125
13  1975     2411732  ...       4079480606                 126
14  1970     2150707  ...       3700437046                 125
15  1965     1896171  ...       3339583597                 127
16  1960     1636090  ...       3034949748                 124
17  1955     1419994  ...       2773019936                 127

[18 rows x 13 columns]



print(forecast_population)
     Year  Population  ... World Population  AlbaniaGlobal Rank
0     NaN         NaN  ...              NaN                 NaN
1  2020.0   2877797.0  ...     7.794799e+09               140.0
2  2025.0   2840464.0  ...     8.184437e+09               141.0
3  2030.0   2786974.0  ...     8.548487e+09               143.0
4  2035.0   2721082.0  ...     8.887524e+09               145.0
5  2040.0   2634384.0  ...     9.198847e+09               146.0
6  2045.0   2533645.0  ...     9.481803e+09               147.0
7  2050.0   2424061.0  ...     9.735034e+09               148.0

[8 rows x 13 columns]