python convert a binary number to a decimal number

1def binToDec(num):
2
3    temp = str(num)
4    arr = []
5    final = []
6
7    for i in temp:
8        arr.append(i)
9
10    arrNums = [str(x) for x in arr]
11    arrNums.reverse()
12
13    j = 0
14    for i in range(0, len(arrNums)):
15        factor = arrNums[i]*(2**j)
16        j += 1
17        final.append(factor)
18
19    decimal = 0
20    for i in range(0, len(final)):
21        decimal += final[i]
22
23    return decimal
24
25if __name__ == "__main__":
26	num = 101000
27    print(binToDec(num)) # Expected Output : 40

1format(decimal ,"b")
2