Euler #93

from itertools import permutations


def apply(uno, dos, num):
    if num == 1:
        return uno + dos
    if num == 2:
        return uno - dos
    if num == 3:
        return uno * dos
    if num == 4:
        return uno / dos


def churn(listing, lineup):
    modifier = 0
    for operator in lineup:
        if operator[1] == 2:
            listing[2 - modifier] = apply(listing[2 - modifier], listing[2 - modifier + 1], operator[0])
            listing[2 - modifier + 1] = ""
            listing.pop(listing.index(""))
        if operator[1] == 1:
            listing[1 - modifier] = apply(listing[1 - modifier], listing[1 - modifier + 1], operator[0])
            listing[1 - modifier + 1] = ""
            listing.pop(listing.index(""))
            modifier += 1
        if operator[1] == 0:
            listing[0] = apply(listing[0], listing[1], operator[0])
            listing[1] = ""
            listing.pop(listing.index(""))
            modifier += 1
    return listing[0]


operators = []
for first in range(1, 5):
    for second in range(1, 5):
        for third in range(1, 5):
            operators.append([first, second, third])

digits = []
for one in range(1, 10):
    for two in range(one + 1, 10):
        for three in range(two + 1, 10):
            for four in range(three + 1, 10):
                if len([one, two, three, four]) == len({one, two, three, four}):
                    digits.append([one, two, three, four])

best, answer = 0, []
for x in digits:
    chain = []
    for y in permutations(x):
        y = list(y)
        for a in operators:
            for b in permutations([0, 1, 2]):
                try:
                    entry = churn([y[0], y[1], y[2], y[3]], zip(a, b))
                    if entry > 0 and abs(round(entry) - entry) < 0.0000000005 and round(entry) not in chain:
                        chain.append(round(entry))
                except ZeroDivisionError:
                    pass
    starting, length = 0, 0
    for z in sorted(set(chain)):
        if z != starting + 1:
            if length > best:
                best = length
                answer = x
            break
        starting += 1
        length += 1
print(best, answer)