Web scraping job postings from Facebook I built a web scraper to pull a list of jobs on Facebook and other websites but want to break up the code into functions that I can reuse for other websites. This structure is working but I think it can be more efficient with functions. I'm getting stuck on how to structure the functions. It's only pulling two pages for testing.

from time import time
from requests import get
from time import sleep
from random import randint
from IPython.core.display import clear_output
from warnings import warn
from bs4 import BeautifulSoup
import csv

# Range of only 2 pages
pages = [str(i) for i in range(1, 3)]
cities = ["Menlo%20Park%2C%20CA",
          "Fremont%2C%20CA",
          "Los%20Angeles%2C%20CA",
          "Mountain%20View%2C%20CA",
          "Northridge%2CCA",
          "Redmond%2C%20WA",
          "San%20Francisco%2C%20CA",
          "Santa%20Clara%2C%20CA",
          "Seattle%2C%20WA",
          "Woodland%20Hills%2C%20CA"]

# Preparing the monitoring of the loop
start_time = time()
requests = 0

with open('facebook_job_list.csv', 'w', newline='') as f:
    header = csv.writer(f)
    header.writerow(["Website", "Title", "Location", "Job URL"])

for page in pages:
    for c in cities:
        # Requests the html page
        response = get("https://www.facebook.com/careers/jobs/?page=" + page +
                       "&amp;results_per_page=100&amp;locations[0]=" + c)

        # Pauses the loop between 8 and 15 seconds
        sleep(randint(8, 15))

        # Monitor the frequency of requests
        requests += 1
        elapsed_time = time() - start_time
        print("Request:{}; Frequency: {} request/s".format(requests, requests/elapsed_time))
        clear_output(wait=True)

        # Throw a warning for non-200 status codes
        if response.status_code != 200:
            warn("Request: {}; Status code: {}".format(requests, response.status_code))

        # Break the loop if number of requests is greater than expected
        if requests &gt; 2:
            warn("Number of requests was greater than expected.")
            break

        # Parse the content of the request with BeautifulSoup
        page_soup = BeautifulSoup(response.text, 'html.parser')
        job_containers = page_soup.find_all("a", "_69jm")

        # Select all 100 jobs containers from a single page
        for container in job_containers:
            site = page_soup.find("title").text
            title = container.find("div", "_69jo").text
            location = container.find("div", "_1n-z _6hy- _21-h").text
            link = container.get("href")
            job_link = "https://www.facebook.com" + link

            with open('facebook_job_list.csv', 'a', newline='') as f:
                rows = csv.writer(f)
                rows.writerow([site, title, location, job_link])
Some quick suggestions: 

The requests module can urlencode strings for you if you use the params keyword:

import requests

cities = ["Menlo Park, CA"]
pages = range(1, 3)
url = "https://www.facebook.com/careers/jobs/"

for city in cities:
    for page in pages:
        params = {"page": page, "results_per_page": 100, "locations[0]": city}
        response = requests.get(url, params=params)


Organize your code using functions. This allows you to give them a readable name (and even add docstrings).

def get_job_infos(response):
    """Parse the content of the request to get all job postings"""
    page_soup = BeautifulSoup(response.text, 'lxml')
    job_containers = page_soup.find_all("a", "_69jm")

    # Select all 100 jobs containers from a single page
    for container in job_containers:
        site = page_soup.find("title").text
        title = container.find("div", "_69jo").text
        location = container.find("div", "_1n-z _6hy- _21-h").text
        job_link = "https://www.facebook.com" + container.get("href")
        yield site, title, location, job_link


This is a generator over which you can iterate. Using the lxml parser is usually faster.

Note that csv can write multiple rows at once using writer.writerows, which takes any iterable of rows:

with open('facebook_job_list.csv', 'a', newline='') as f:
    writer = csv.writer(f)
    writer.writerows(get_job_infos(response))


This way you only have to open the file once per page, instead of a hundred times. Even better would be to make the whole thing a generator, so you can write all rows while opening the file only once:

def get_all_jobs(url, cities, pages):
    for city in cities:
        for page in pages:
            params = {"page": page, "results_per_page": 100, "locations[0]": city}
            response = requests.get(url, params=params)
            # check status code

            yield from get_job_infos(response)

            # rate throttling, etc here
            ...

if __name__ == "__main__":
    cities = ["Menlo Park, CA", ...]
    pages = range(1, 3)
    url = "https://www.facebook.com/careers/jobs/"

    with open('facebook_job_list.csv', "w") as f:
        writer = csv.writer(f)
        writer.writerow(["Website", "Title", "Location", "Job URL"])
        writer.writerows(get_all_jobs(url, pages, cities))


This way the get_all_jobs generator will yield jobs as it is being iterated over, getting the next page when needed.