Local variable returning Nonetype Error Python

I am trying to build a function for looping through to subsequent pages of a website and scraping data from each. I am getting the following nonetype error and I don't know how to get around it:

if not page.find('a', {'class': 'btn btn-default current disabled'}): AttributeError: 'NoneType' object has no attribute 'find'

from bs4 import *
import time
import pandas as pd
import pickle
import html5lib
from requests_html import HTMLSession

s = HTMLSession()
url = "https://cryptoli.st/lists/fixed-supply"


def get_data(url):
    r = s.get(url)
    global soup
    soup = BeautifulSoup(r.text, 'html.parser')
    return soup
    


def get_next_page(data):
    page = soup.find('ul', {'class': 'pager'})
    if not page.find('a', {'class': 'btn btn-default current disabled'}):
        url = 'https://cryptoli.st/lists/fixed-supply' + \
            str(page.find('li', {'class': 'paginate_button'}).find(
                'a')[{'class': 'btn btn-default next'}])
        return url
    else:
        return


data = get_data(url)
print(get_next_page(soup))

Any help would be greatly appreciated.

Solution

From BeautifulSoup docs:

If find() can’t find anything, it returns None:
print(soup.find("nosuchtag"))
# None

That means that most likely this:

soup.find('ul', {'class': 'pager'})

returns None. Make sure that such element exists in the site you're trying to parse. It could be that the static HTML doesn't include it, and the list is populated dynamically.

Indeed, if in chrome you go to view-source:https://cryptoli.st/lists/fixed-supply, you will see that there is no <ul class="pager" anywhere.