intern_supply.py

from urllib.request import urlopen
from bs4 import BeautifulSoup
from email.mime.text import MIMEText
import re
import argparse
import time
import datetime
import smtplib
try:
	import lxml
	PARSER = "lxml" # Faster parser
except ImportError:
	PARSER = "html.parser" # Use html.parser if lxml not installed
	
URL = "http://www.intern.supply"
INFO = """
Script to track the website Intern Supply ({}). Sends the user an email when a desired internship opens.""".format(URL)
SRC = """
For companies with longer names (more than one word), put doubles quotes (\") around the full name.
Not all companies are available; check {} for the full list.

Written by Jeremiah Fan""".format(URL)
TXT = """
The following internship applications are now available: {}
This email was automatically generated by a script at {}."""

def checkAvailable(text):
	if text == "Not Yet Available":
		return {"status": "Not Available", "availability": False}
	return {"status": "Available", "availability": True} # As opposed to "Apply" which is presented on website

def sendMail(availList):
	e_usr = fhandle.readline() # fhandle initialized in main()
	e_pwd = fhandle.readline()
	
	msg = MIMEText(TXT.format(', '.join(availList), datetime.datetime.now().isoformat(sep=' ')))
	msg['Subject'] = "Internship Applications Open"
	msg['From'] = e_usr
	if RECIPIENT == None:
		msg['To'] = e_usr # If -e option not specified, send email to self
	else:
		msg['To'] = RECIPIENT

	s = smtplib.SMTP('smtp.gmail.com', 587) # Send via Gmail's SMTP server
	s.starttls() # Upgrade to secure connection, requirement by Gmail
	s.login(e_usr, e_pwd)
	s.send_message(msg)
	print("Email successfully sent to {}".format(msg['To'].rstrip())) # Print out success message
	s.quit()

def formatCompanies(inputList): # Check companies' existence and format them to save us time later
	contents = urlopen(URL).read()
	soup = BeautifulSoup(contents, PARSER) # Slightly inefficient, first iteration of our check later on doesn't use this data, when ideally it would
	for index in range(len(inputList)):
		clean = re.sub(' +', ' ', inputList[index].strip()) # Strip leading, trailing, and duplicate whitespaces
		navStr = soup.find(text=re.compile("^{}$".format(clean), re.I))
		if navStr == None:
			print('intern_supply.py: error: {} - No company by this name could be found.'.format(clean))
			exit(1)
		inputList[index] = navStr
	return inputList

def checkCompanies(companyList):
	contents = urlopen(URL).read()
	soup = BeautifulSoup(contents, PARSER)
	availList = list()
	for company in companyList:
		navStr = soup.find(text=company)
		check = checkAvailable(navStr.next.text) # Check the text of the tag following the text containing the company's name
		if check["availability"]:
			availList.append(navStr)
		print("{}:".format(navStr), check["status"])
	
	if len(availList) > 0:
		print("\nRemoving {} from query".format(", ".join(availList)))
		sendMail(availList)
	return [x for x in companyList if x not in availList] # Remove the available internships from our query
		
def main():
	print("Initiating Intern Supply Detector...\n")
	
	COMPANYLIST = formatCompanies(args.COMPANY) # The list of companies should not be a global variable, so we first access it here
	while True:
		COMPANYLIST = checkCompanies(COMPANYLIST) # Check list of companies
		if len(COMPANYLIST) <= 0: # If all of the companies we want to check are available, we are done
			break
		print("Checking again in another {} minutes\n".format(WAITTIME))
		time.sleep(WAITTIME * 60) # time.time.sleep() treats argument as seconds

if __name__ == "__main__":
	parser = argparse.ArgumentParser(description = INFO, epilog = SRC)
	parser.add_argument('COMPANY', nargs='+', help='Name of company to track')
	parser.add_argument('--interval', '-i', metavar='N', type=float, default=5, help='Interval between queries in minutes')
	parser.add_argument('--email', '-e', metavar='E', help='Email address to send notification message to')
	args = parser.parse_args()
	WAITTIME = args.interval # Initialize WAITTIME and RECIPIENT here, they should have global scope
	RECIPIENT = args.email
	
	try:
		fhandle = open('.creds') # Execution should stop immediately if '.creds' does not exist, should have global scope
	except:
		print("intern_supply.py: error: no file '.creds' containing email username and password was found. Unable to send email.")
		exit(1)
		
	main()