问题
I'm trying to scrape the data from the coins catalog.
There is one of the pages. I need to scrape this data into Dataframe
So far I have this code:
import bs4 as bs
import urllib.request
import pandas as pd
source = urllib.request.urlopen('http://www.gcoins.net/en/catalog/view/45518').read()
soup = bs.BeautifulSoup(source,'lxml')
table = soup.find('table', attrs={'class':'subs noBorders evenRows'})
table_rows = table.find_all('tr')
for tr in table_rows:
td = tr.find_all('td')
row = [tr.text for tr in td]
print(row) # I need to save this data instead of printing it
It produces following output:
[]
['', '', '1882', '', '108,000', 'UNC', '—']
[' ', '', '1883', '', '786,000', 'UNC', '~ $3.99']
[' ', " \n\n\n\n\t\t\t\t\t\t\t$('subGraph55337').on('click', function(event) {\n\t\t\t\t\t\t\t\tLightview.show({\n\t\t\t\t\t\t\t\t\thref : '/en/catalog/ajax/subgraph?id=55337',\n\t\t\t\t\t\t\t\t\trel : 'ajax',\n\t\t\t\t\t\t\t\t\toptions : {\n\t\t\t\t\t\t\t\t\t\tautosize : true,\n\t\t\t\t\t\t\t\t\t\ttopclose : true,\n\t\t\t\t\t\t\t\t\t\tajax : {\n\t\t\t\t\t\t\t\t\t\t\tevalScripts : true\n\t\t\t\t\t\t\t\t\t\t}\n\t\t\t\t\t\t\t\t\t} \n\t\t\t\t\t\t\t\t});\n\t\t\t\t\t\t\t\tevent.stop();\n\t\t\t\t\t\t\t\treturn false;\n\t\t\t\t\t\t\t});\n\t\t\t\t\t\t", '1884', '', '4,604,000', 'UNC', '~ $2.08–$4.47']
[' ', '', '1885', '', '1,314,000', 'UNC', '~ $3.20']
['', '', '1886', '', '444,000', 'UNC', '—']
[' ', '', '1888', '', '413,000', 'UNC', '~ $2.88']
[' ', '', '1889', '', '568,000', 'UNC', '~ $2.56']
[' ', " \n\n\n\n\t\t\t\t\t\t\t$('subGraph55342').on('click', function(event) {\n\t\t\t\t\t\t\t\tLightview.show({\n\t\t\t\t\t\t\t\t\thref : '/en/catalog/ajax/subgraph?id=55342',\n\t\t\t\t\t\t\t\t\trel : 'ajax',\n\t\t\t\t\t\t\t\t\toptions : {\n\t\t\t\t\t\t\t\t\t\tautosize : true,\n\t\t\t\t\t\t\t\t\t\ttopclose : true,\n\t\t\t\t\t\t\t\t\t\tajax : {\n\t\t\t\t\t\t\t\t\t\t\tevalScripts : true\n\t\t\t\t\t\t\t\t\t\t}\n\t\t\t\t\t\t\t\t\t} \n\t\t\t\t\t\t\t\t});\n\t\t\t\t\t\t\t\tevent.stop();\n\t\t\t\t\t\t\t\treturn false;\n\t\t\t\t\t\t\t});\n\t\t\t\t\t\t", '1890', '', '2,137,000', 'UNC', '~ $1.28–$4.79']
['', '', '1891', '', '605,000', 'UNC', '—']
[' ', '', '1892', '', '205,000', 'UNC', '~ $4.47']
[' ', '', '1893', '', '754,000', 'UNC', '~ $4.79']
[' ', '', '1894', '', '532,000', 'UNC', '~ $3.20']
[' ', '', '1895', '', '423,000', 'UNC', '~ $2.40']
['', '', '1896', '', '174,000', 'UNC', '—']
But when I'm trying to save it to Dataframe and export to excel it contains just the last value:
0
0
1
2 1896
3
4 174,000
5 UNC
6 —
回答1:
Try this
l = []
for tr in table_rows:
td = tr.find_all('td')
row = [tr.text for tr in td]
l.append(row)
pd.DataFrame(l, columns=["A", "B", ...])
回答2:
Pandas already has a built-in method to convert the table on the web to a dataframe:
table = soup.find_all('table')
df = pd.read_html(str(table))[0]
回答3:
Try:
import pandas as pd
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, "html.parser")
table = soup.find('table', attrs={'class':'subs noBorders evenRows'})
table_rows = table.find_all('tr')
res = []
for tr in table_rows:
td = tr.find_all('td')
row = [tr.text.strip() for tr in td if tr.text.strip()]
if row:
res.append(row)
df = pd.DataFrame(res, columns=["Year", "Mintage", "Quality", "Price"])
print(df)
Output:
Year Mintage Quality Price
0 1882 108,000 UNC —
1 1883 786,000 UNC ~ $4.03
回答4:
Just a head's up... This part of Rakesh's code means that only HTML rows containing text will be included in the dataframe, as the rows don't get appended if row is an empty list:
if row:
res.append(row)
Problematic in my use case, where I wanted to compare row indexing for the HTML and dataframe tables later on. I just needed to change it to:
res.append(row)
Also, if a cell in the row is empty, it doesn't get included. This then messes up the columns. So I changed
row = [tr.text.strip() for tr in td if tr.text.strip()]
to
row = [d.text.strip() for d in td]
But, otherwise, it's working for me. Thanks :)
来源：https://stackoverflow.com/questions/50633050/scrape-tables-into-dataframe-with-beautifulsoup