Как сделать отступы в морской бой?

Question

[5HT2A]

Написал ф-ию которая наугад заполняет матрицу кораблями 4, 3, 2, 1 палубными, на рандом либо вертикально, либо горизонтально, но в ней не предусмотрено правило: "При размещении корабли не могут касаться друг друга сторонами и углами." Переделал с огромным кол-вом условий, чтобы были отступы, но не выходило за границы массива, но работает через раз... Подскажите где исправить?, либо как иначе их сделать ?

Без отступов

from random import randint

N = 10

def move():
    r = randint(0,1)
    if r:
        print("Ваш ход")
    else:
        print("Мой ход")
    return r
            
def field(a):
    for i in a:
        for el in i:
            print(el, end=' ') 
        print()

def ship(n,a):
    f = 0
    b = []
    while not f:
        r1 = randint(0,1)
        r2 = randint(0,N-n)
        r3 = randint(0,9)
        k = 0

        if r1:
            for i in range(r2,r2+n):        #В строку 
                if a[r3][i] == 0:
                    k += 1
                
                if k == n:
                    for i in range(r2,r2+n):
                        a[r3][i] = n
                        #b.append((r3,i))
                    f = 1
                
        else:
            for i in range(r2,r2+n):        #В столбец
                if a[i][r3] == 0:
                    k += 1
                    
                if k == n:
                    for i in range(r2,r2+n):
                        a[i][r3] = n
                        #b.append((i,r3))
                    f = 1
    return a

def check(a):
    f = 0
    for i in range(len(a)):
        for j in range(len(a)):
            if a[i][j] == 0:
                f = 1
            else:
                f = 0
    return f
    
def shoot(t,b):
    
    line = "0123456789"
    f = 0
    s2 = 2
    s3 = 3
    s4 = 4
    if a[t0][t1] == 0:
        print("Мимо")
    elif a[t0][t1] == 1:
        print("Убил")
        a[t0][t1] = 0
        f = 1
    elif a[t0][t1] == 2:
        print("Попал")
        a[t0][t1] = 0
        b.remove((t0,t1))
        f = 1
        if not b:
            print("Убил")
            
    return f
    
        

def draw(a):    
    a = ship(4,a)
    a = ship(3,a) 
    a = ship(3,a)
    a = ship(2,a)
    a = ship(2,a)
    a = ship(2,a) 
    a = ship(1,a)
    a = ship(1,a)
    a = ship(1,a)
    a = ship(1,a)
    field(a)


a = [[0] * 10 for i in range(N)]

draw(a)
f = move()

С отступами и ошибкой

from random import randint

N = 10 
                
def move():
    r = randint(0,1)
    if r:
        print("Ваш ход")
    else:
        print("Мой ход")
    return r
            
def field(a):
    for i in a:
        for el in i:
            print(el, end=' ') 
        print()

def ship(n,a):
    f = 0
    b = []
    while not f:
        r1 = 1 #Временно заполняем только в строку
        r2 = randint(0,N-n)
        r3 = randint(0,9)
        k = 0

        if r1:
            for i in range(r2,r2+n):        #В строку 
                if a[r3][i] == 0:
                    k += 1
                
                if k == n:
                    for i in range(r2,r2+n):
                        a[r3][i] = n
                        
                    if r3 == 0 and r2 == 0:
                        a[r3][n] = 5
                        for i in range(r2,r2+n+1):
                            a[r3+1][i] = 5
                            
                    elif r3 == 9 and r2 == 0:
                        a[r3][n] = 5
                        for i in range(r2,r2+n+1):
                            a[r3-1][i] = 5
                            
                    elif r3 == 0 and r2 == N-n:
                        a[r3][r2-1] = 5
                        for i in range(r2-1,r2+n):
                            a[r3+1][i] = 5

                    elif r3 == 9 and r2 == N-n:
                        a[r3][r2-1] = 5
                        for i in range(r2-1,r2+n):
                            a[r3-1][i] = 5

                    elif r3 == 0 and r2 > 0 and r2 < 9:
                        a[r3][r2-1] = 5
                        a[r3][r2+n] = 5
                        for i in range(r2-1,r2+n+1):
                            a[r3+1][i] = 5

                    elif r3 == 9 and r2 > 0 and r2 < 9:
                        a[r3][r2-1] = 5
                        a[r3][r2+n] = 5
                        for i in range(r2-1,r2+n+1):
                            a[r3-1][i] = 5

                    elif r2 == 0 and r3 > 0 and r3 < 9:
                        a[r3][n] = 5
                        for i in range(r2,r2+n+1):
                            a[r3-1][i] = 5
                            a[r3+1][i] = 5

                    elif r2 == 9 and r3 > 0 and r3 < 9:
                        a[r3][n+1] = 5
                        for i in range(N-n-1,N):
                            a[r3-1][i] = 5
                            a[r3+1][i] = 5
                    
                    else:
                        a[r3][r2-1] = 5
                        a[r3][r2+n] = 5
                        for i in range(r2-1,r2+n+1):
                            a[r3+1][i] = 5
                            a[r3-1][i] = 5
                        #b.append((r3,i))
                    f = 1
                
        else:
            for i in range(r2,r2+n):        #В столбец
                if a[i][r3] == 0:
                    k += 1
                    
                if k == n:
                    for i in range(r2,r2+n):
                        a[i][r3] = n
                        #b.append((i,r3))
                    f = 1
    return a

def check(a):
    f = 0
    for i in range(len(a)):
        for j in range(len(a)):
            if a[i][j] == 0:
                f = 1
            else:
                f = 0
    return f


    
def shoot(t,b):
    
    line = "0123456789"
    f = 0
    s2 = 2
    s3 = 3
    s4 = 4
    if a[t0][t1] == 0:
        print("Мимо")
    elif a[t0][t1] == 1:
        print("Убил")
        a[t0][t1] = 0
        f = 1
    elif a[t0][t1] == 2:
        print("Попал")
        a[t0][t1] = 0
        b.remove((t0,t1))
        f = 1
        if not b:
            print("Убил")
            
    return f
    
        

def draw(a):    
    a = ship(4,a)
    a = ship(3,a) 
    a = ship(3,a)
    a = ship(2,a)
    a = ship(2,a)
    a = ship(2,a) 
    a = ship(1,a)
    a = ship(1,a)
    a = ship(1,a)
    a = ship(1,a)
    field(a)


a = [[0] * 10 for i in range(N)]

draw(a)
f = move()

Answer 1

[longclaps]

Многобукв, и кто даёт такие имена переменным - тот **дак.

from random import randint, choice


def neighbours(cells):
    return {(i, j) for y, x in cells
            for i in range(y - 1, y + 2) for j in range(x - 1, x + 2)}


N = 10  # а вот менять не надо
abc, digits = 'abcdefghij', '0123456789'
field, sea_map = {}, [[' '] * N for _ in range(N)]
for size in 4, 3, 3, 2, 2, 2, 1, 1, 1, 1:
    while True:
        ship = [(randint(0, N - 1), randint(0, N - 1))]
        for _ in range(1, size):
            ship.append(choice([(i, j) for y, x in ship for i, j in (
                (y - 1, x), (y, x - 1), (y, x + 1), (y + 1, x)
            ) if 0 <= i < N > j >= 0 and (i, j) not in ship]))
        if not neighbours(ship) & field.keys():
            break
    field.update(dict.fromkeys(ship, ship))
fleet = set(field)

for step in range(1, 51):  # ограничимся 50ю ходами
    print('    0 1 2 3 4 5 6 7 8 9 \n  ┌─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┐')
    for ch, row in zip(abc, sea_map):
        print(ch, '┤', *row, '├', ch)
    print('  └─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┘\n    0 1 2 3 4 5 6 7 8 9')
    s = input(f'{step:>2}  Ваш ход: ')
    try:
        y, x = abc.index(s[0]), digits.index(s[1])
        ship, row = field.get((y, x), ), sea_map[y]
        if ship:
            del field[y, x]
            row[x] = '*'
            print(s, 'Попал\n' if ship & field.keys() else 'Убил\n')
            if not field:
                print('Победа!')
                break
        else:
            if row[x] == ' ':
                row[x] = str(len(fleet & neighbours([(y, x)])))
            print(s, 'Мимо\n')
    except:
        print('Ожидался ход в формате \'a0\', но что-то пошло не так...\n')
else:
    print(f'В этот раз не вышло, в строю осталось {len(field)} палуб '
          f'на {len({id(ship) for ship in field.values()})} кораблях.')