from itertools import permutations


def solve() -> int:
    pandigital = []

    for permutation in permutations(range(1, 10)):
        result = int(''.join(str(digit) for digit in permutation[:4]))

        for i in range(1, 4):
            left = int(''.join(str(digit) for digit in permutation[4:4 + i]))
            right = int(''.join(str(digit) for digit in permutation[4 + i:]))

            if left * right == result:
                pandigital.append(result)

    return sum(set(pandigital))

from itertools import permutations

from ..library.base import list_to_number


def solve() -> int:
    pandigital = []

    for permutation in permutations(range(1, 10)):
        result = list_to_number(permutation[:4])

        for i in range(1, 4):
            left = list_to_number(permutation[4:4 + i])
            right = list_to_number(permutation[4 + i:])

            if left * right == result:
                pandigital.append(result)

    return sum(set(pandigital))

Replace joins with list_to_number in 32
Replace joins with list_to_number in 32

  from itertools import permutations
+ 
+ from ..library.base import list_to_number
  
  
  def solve() -> int:
      pandigital = []
  
      for permutation in permutations(range(1, 10)):
-         result = int(''.join(str(digit) for digit in permutation[:4]))
+         result = list_to_number(permutation[:4])
  
          for i in range(1, 4):
-             left = int(''.join(str(digit) for digit in permutation[4:4 + i]))
-             right = int(''.join(str(digit) for digit in permutation[4 + i:]))
+             left = list_to_number(permutation[4:4 + i])
+             right = list_to_number(permutation[4 + i:])
  
              if left * right == result:
                  pandigital.append(result)
  
      return sum(set(pandigital))
  
Replace joins with list_to_number in 32
## Code Before:
from itertools import permutations


def solve() -> int:
    pandigital = []

    for permutation in permutations(range(1, 10)):
        result = int(''.join(str(digit) for digit in permutation[:4]))

        for i in range(1, 4):
            left = int(''.join(str(digit) for digit in permutation[4:4 + i]))
            right = int(''.join(str(digit) for digit in permutation[4 + i:]))

            if left * right == result:
                pandigital.append(result)

    return sum(set(pandigital))

## Instruction:
Replace joins with list_to_number in 32
## Code After:
from itertools import permutations

from ..library.base import list_to_number


def solve() -> int:
    pandigital = []

    for permutation in permutations(range(1, 10)):
        result = list_to_number(permutation[:4])

        for i in range(1, 4):
            left = list_to_number(permutation[4:4 + i])
            right = list_to_number(permutation[4 + i:])

            if left * right == result:
                pandigital.append(result)

    return sum(set(pandigital))
