# With unmodified `main` function & `import string` not shown
In [4]: with open("inputs/day13.txt", "r") as f:
   ...:     input_data = f.read().strip().replace(',', '').split('\n\n')
   ...:

In [5]: part_one, part_two = main(input_data)

In [6]: part_one
Out[6]: 39748

In [7]: part_two
Out[7]: 74926346266863

# Then I modified the function to check if x is fractional
In [8]: def main(input_data):
   ...:     part1_total_cost = 0
   ...:     part2_total_cost = 0
   ...:     for machine in input_data:
   ...:         Ax,Ay,Bx,By,Px,Py = [ int(l[2:]) for l in machine.split() if l[-1] in string.digits ]
   ...:         y,r = divmod((Ay * Px - Ax * Py), (Ay * Bx - Ax * By))
   ...:         if r == 0:
   ...:             x = (Px - Bx * y) / Ax
   ...:             if x % 1 == 0:
   ...:                 part1_total_cost += 3*x + y
   ...:         y,r = divmod((Ay * (Px+10000000000000) - Ax * (Py+10000000000000)), (Ay * Bx - Ax * By))
   ...:         if r == 0:
   ...:             x = ((Px+10000000000000) - Bx * y) / Ax
   ...:             if x % 1 == 0:
   ...:                 part2_total_cost += 3*x + y
   ...:
   ...:     return part1_total_cost,part2_total_cost
   ...:

In [9]: part_one, part_two = main(input_data)

In [10]: part_one
Out[10]: 39748.0

In [11]: part_two
Out[11]: 74478585072604.0  # Correct answer for pt 2 of my input