This answered my question, problem solved. You may delete this post.
RETRIES = 10
id = None
session = requests.Session()
for attempt in range(1, RETRIES + 1):
response = session.get(url)
soup = BeautifulSoup(r.text, "lxml")
element = soup.find('a', class_="class", id=True)
if element is None:
print("Attempt {attempt}. Element not found".format(attempt=attempt))
continue
else:
id = element["id"]
break
print(id)
This answered my question, problem solved. You may delete this post.
You can apply the "look before you leap" ( LBYL
) principle and check the result of find()
- it would return None
if an element was not found. You can then put the thing into a loop and exit when you have a value, also safeguarding yourself with a loop counter limit:
RETRIES = 10
id = None
session = requests.Session()
for attempt in range(1, RETRIES + 1):
response = session.get(url)
soup = BeautifulSoup(r.text, "lxml")
element = soup.find('a', class_="class", id=True)
if element is None:
print("Attempt {attempt}. Element not found".format(attempt=attempt))
continue
else:
id = element["id"]
break
print(id)
Couple notes:
id=True
was set to find only elements with the id
element present. You could also do an equivalent with a CSS selector soup.select_one("a.class[id]")
Session()
helps to improve performance when issuing requests to the same host multiple times. See more at Session ObjectsIf all you want to do is make that same request a second time, you could do something like this:
import requests
from bs4 import BeautifulSoup
def find_data(url):
found_data = False
while not found_data:
r = requests.get(url)
soup = BeautifulSoup(r.text, "lxml")
try:
id = soup.find('a', class_="class").get('id')
found_data = True
except:
pass
This puts you at risk of an infinite loop if the data really aren't there. You can do this to avoid that infinite loop:
import requests
from bs4 import BeautifulSoup
def find_data(url, attempts_before_fail=3):
found_data = False
while not found_data:
r = requests.get(url)
soup = BeautifulSoup(r.text, "lxml")
try:
id = soup.find('a', class_="class").get('id')
found_data = True
except:
attempts_before_fail -= 1
if attempts_before_fail == 0:
raise ValueError("couldn't find data after all.")
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