使用Python和Beautiful Soup从表中获取列

Question

I am new to Python and I want to get the "price" column of data from a table however I'm unable to retrieve that data.

Currently what I'm doing:

# Libraies
from urllib.request import urlopen
from bs4 import BeautifulSoup

html = urlopen("http://pythonscraping.com/pages/page3.html")
soup = BeautifulSoup(html, "html.parser")
table = soup.find("table")

for row in table.find_all("tr"):

    col = row.find_all("td")

    print(col[2])
    print("---")

I keep getting a list index out of value range. I've read the documentation and tried a few different ways, but I can't seem to get it down.

Also, I am using Python3.

Answer 1

The problem is that you are iterating over all tr inside the table, and there is 1 header tr at the beginning that you don't need, so just avoid using that one:

    # Libraies
from urllib.request import urlopen
from bs4 import BeautifulSoup

html = urlopen("http://pythonscraping.com/pages/page3.html")
soup = BeautifulSoup(html, "html.parser")
table = soup.find("table")

for row in table.find_all("tr")[1:]:

    col = row.find_all("td")

    print(col[2])
    print("---")

Answer 2

Probably means that one of the rows has no td tag. You could wrap the print or whatever usage of col[2] in a try except block and ignore cases where the col is empty or has less than three items

for row in table.find_all("tr"):

    col = row.find_all("td")
    try:  
        print(col[2])
        print("---")
    except IndexError:
        pass