Check relations of paths in OSM

check.py

#!/usr/bin/python

from shapely import geometry, ops
import overpy, smtplib, sqlite3, os
from datetime import date

trails = {
	'שביל הגולן': 568661,
#	'גב חולית': 4084669,
	'שביל ישראל': 282071,
	# 'סובב מכתש רמון': 6148296,
	'ים אל ים': 2860967,
#	'שמורת מדבר יהודה': 8813797,
	'שביל השרון': 11518999,
        3418441: 'שביל רמות מנשה',
}

# email settings
from settings import email_to, email_from

today = date.today().strftime('%Y-%m-%d')

con = sqlite3.connect(os.path.dirname(os.path.abspath(__file__)) + '/rels.db')
cur = con.cursor()
cur.execute('create table if not exists history (rel, version, date)')

def checkRel(rel):
	query = """[out:json][timeout:25];
	rel({});
	out meta;
	out body;
	>;
	out skel qt; """.format(rel)
	api = overpy.Overpass()
	result = api.query(query)

	global version
	version = result.relations[0].attributes.get('version')
	

	if relInHistory(rel, version):
		return True

	lss = [] #convert ways to linstrings

	for ii_w,way in enumerate(result.ways):
		ls_coords = []

		for node in way.nodes:
			ls_coords.append((float(node.lon),float(node.lat))) # create a list of node coordinates
			
		lss.append(ls_coords)

	line = geometry.MultiLineString(lss)

	merged_line = ops.linemerge(line)
	is_linestring = True

	try:
		ls = geometry.LineString(merged_line)
	except:
		is_linestring = False
		saveRel(rel, version)

	# print(rel)
	# print('LineString: ' + str(is_linestring))	
	# print('Simple: ' + str(line.is_simple))
	# print('Valid: ' + str(line.is_valid))
	# print(' ')
	return is_linestring

def relInHistory(rel, version):
	cur.execute('select * from history where rel = ? and version = ? and date = ?', (rel, version, today))
	data = cur.fetchone()
	return data is not None

def saveRel(rel, version):
	cur.execute('insert into history(rel, version, date) values(?, ?, ?)', (rel, version, today))
	con.commit()

def sendEmail(trail):
	global version
	server = smtplib.SMTP('localhost')
	subject = 'היחס {} שבור'.format(trail)
	message = """Subject: {0}

	{1} שבור. כדאי לבדוק אותו:
	גרסה: {2}
	https://israelhiking.osm.org.il/poi/OSM/relation_{3}
	https://www.openstreetmap.org/relation/{3}
	http://ra.osmsurround.org/analyzeRelation?relationId={3}&noCache=true&_noCache=on""".format(subject, trail, version, trails[trail]).encode('utf-8')


	server.sendmail(email_from, email_to, message)
	# print('alert sent')

for trail in trails:
	if not checkRel(trails[trail]):
		print(trail)
		sendEmail(trail)

#https://stackoverflow.com/questions/60670206/how-do-i-get-the-geometry-of-a-relation-from-openstreetmap
#https://www.facebook.com/groups/lost.geographers/posts/4574980922621550/