Shortest route between stations coverign all the vowels with their names

metro-vowels.py

from itertools import combinations
stations = ["Airport", "Bank Foot", "Bede", "Benton", "Brockley Whins", "Byker", "Callerton Parkway", "Central Station", "Chichester", "Chillingham Road", "Cullercoats", "East Boldon", "Fawdon", "Fellgate", "Felling", "Four Lane Ends", "Gateshead", "Gateshead Stadium", "Hadrian Road", "Haymarket", "Hebburn", "Heworth", "Howdon", "Ilford Road", "Jarrow", "Jesmond", "Kingston Park", "Longbenton", "Manors", "Meadow Well", "Millfield", "Monkseaton", "Monument", "North Shields", "Northumberland Park", "Pallion", "Palmersville", "Park Lane", "Pelaw", "Percy Main", "Regent Centre", "Seaburn", "Shiremoor", "Simonside", "South Gosforth", "South Hylton", "South Shields", "St James", "St Peter's", "Stadium of Light", "Sunderland", "Tyne Dock", "Tynemouth", "University", "Walkergate", "Wallsend", "Wansbeck Road", "West Jesmond", "West Monkseaton", "Whitley Bay"]
green_line = ["Airport","Callerton Parkway","Bank Foot","Kingston Park","Fawdon","Wansbeck Road","Regent Centre","South Gosforth","Ilford Road","West Jesmond","Jesmond","Haymarket","Monument","Central Station","Gateshead","Gateshead Stadium","Felling","Heworth","Pelaw","Fellgate","Brockley Whins","East Boldon","Seaburn","Stadium of Light","St Peter's","Sunderland","Park Lane","University","Millfield","Pallion","South Hylton"]
yellow_line = ["St James","Monument","Manors","Byker","Chillingham Road","Walkergate","Wallsend","Hadrian Road","Howdon","Percy Main","Meadow Well","North Shields","Tynemouth","Cullercoats","Whitley Bay","Monkseaton","West Monkseaton","Shiremoor","Northumberland Park","Palmersville","Benton","Four Lane Ends","Longbenton","South Gosforth","Ilford Road","West Jesmond","Jesmond","Haymarket","Monument","Central Station","Gateshead","Gateshead Stadium","Felling","Heworth","Pelaw","Hebburn","Jarrow","Bede","Simonside","Tyne Dock","Chichester","South Shields"]
lines = [green_line,yellow_line]
vowels = 'aeiou'

def num_vowels(s):
    s = s.lower()
    return sum(1 if v in s else 0 for v in vowels)

def distance(a,b):
    for line in lines:
        if a in line:
            line_a = line
        if b in line:
            line_b = line
        if a in line and b in line:
            return abs(line.index(a)-line.index(b))
    
    both = [s for s in stations if s in line_a and s in line_b]
    c_distances = [distance(a,x)+distance(x,b) for x in both]
    return min(c_distances)

print(min(((a,b) for a,b in combinations(stations,2) if num_vowels(a+b)==5),key=lambda a: distance(*a)))

Output: (Central station, Monument)