program in binary to decimal in python using array list

Question

Hi I'm new to programming and have a project to create a program to convert binary to decimal in Python. I have to make use of the values stored in the list and multiply based on user input. I keep getting errors regarding int/str.
Any help would be appreciated.Please see code below of what I have so far.

denaryNumber = 0
binaryNumber = input("Please enter binary number: ")
placeValues = [128, 64, 32, 16, 8, 4, 2, 1]
for i in range(0, len(binaryNumber) -1):
 denaryNumber = denaryNumber + (binaryNumber(i) * placeValues[i])
print (denaryNumber)

• user7422128: Can you quote an example here?

Answer 1

There are a few issues in your code.

• Every input by default in python is taken in as 'str' , so your binaryNumber is str
• To access an element from a list, you use[] not () as you have used here: binaryNumber(i)
• Since your binary number is str you cant apply mathematical operations on str , so binaryNumber(i) * placeValues[i] is invalid. You need to type-cast str to int like this : int(binaryNumber[i])
  

So change your 2nd last line to this:

denaryNumber = denaryNumber + (int(binaryNumber[i]) * placeValues[i]) 

It would work then.

jbtw, your code would return correct results only if your input is 8bits.