CODEWITHSUNDEEP
python
Element432
Element432

Reputation: 71

Python: Decimal to Binary

I'm trying to get the function to work, it is suppose to convert Decimal to Binary but all it gives me different numbers instead. Like if I enter 12, it would give me 2. I'm not sure where in the code my issue is located. Any help would be great, thank you!

def decimalToBinary(value):
    if value < 0: #Base case if number is a negative
        return 'Not positive'
    elif value == 0: #Base case if number is zero
        return 0
    else:
        return decimalToBinary(value//2) + (value%2)

Upvotes: 4

Views: 6354

Answers (7)

Ihtisham Ali Farooq
Ihtisham Ali Farooq

Reputation: 442

This may also work 

def DecimalToBinary(number):
        #This function uses recursion to convert & print decimal to binary number
       if number > 1:
           convertToBinary(number//2)
       print(number % 2,end = '')

    # decimal number
    decimal = 34

    convertToBinary(decimal)
    #..........................................
    #it will show output as 110100

Upvotes: 5

Mr. E
Mr. E

Reputation: 2120

I would take another aproach:

def decimalToBinary(number):
    if number<0:
        return 'Not positive'
    i = 0
    result = ''
    while number>>i:
        result = ('1' if number>>i&1 else '0') + result
        i += 1
    return result

Upvotes: 0

Andriy Ivaneyko
Andriy Ivaneyko

Reputation: 22021

You faced error because you adding numbers and not iterables but want to get bits sequences...,so you have to convert values you are adding to tuples or strings (or lists), see code below:

def decimalToBinary(value):
    if value < 0: #Base case if number is a negative
        return 'Not positive'
    elif value == 0: #Base case if number is zero
        return (0,)
    else:
         return decimalToBinary(value//2) + (value%2,)

print decimalToBinary(12)

I've replaced (value%2) to (value%2,) to create tuple(, matter, for python it's mean creating a tuple, braces aren't do it... ) and return 0 to return (0,). However you can convert it to string too. For that replace (value%2) to str(value%2 and 0 to str(0).

Note that you can use built-int bin function ti get binary decimal:

 print bin(12) # 'ob1100'

Good luck in your practice !

Upvotes: 2

B. M.
B. M.

Reputation: 18628

As an exercice, two way :

with strings:

def decimalToBinary(value):
 if value < 0: #Base case if number is a negative
    return 'Not positive'
 elif value == 0: #Base case if number is zero 
    return ''
 else:
     return decimalToBinary(value//2) + str(value%2)

with ints:

def decimalToBinary(value):
 if value < 0: #Base case if number is a negative
    return 'Not positive'
 elif value == 0: #Base case if number is zero 
    return 0
 else:
     return 10*decimalToBinary(value//2) + value%2

In this case, you obtain a decimal whose digits are only 1 or 0.

Upvotes: 0

Aiman Al-Eryani
Aiman Al-Eryani

Reputation: 709

Your problem is that you're adding up the digits of your result in decimal. So if your result was going to be 01100, your function is outputting 0+1+1+0+0 which is equal to 2. If you want your digits to stack up, then convert your results to string and concatenate:

def decimalToBinary(value):
    if value < 0: #Base case if number is a negative
        return 'Not positive'
    elif value == 0: #Base case if number is zero
        return 0
    else:
        return str(decimalToBinary(value//2)) + str((value%2))
print decimalToBinary(12) # prints '01100

I am assuming you're doing this for practice, and that you're aware of python's built in function bin() that already does that for you.

Upvotes: 0

mvelay
mvelay

Reputation: 1520

You should use bin(), a built-in python function

https://docs.python.org/3.1/library/functions.html#bin

Upvotes: 0

G&#225;bor Erdős
G&#225;bor Erdős

Reputation: 3689

What about bin?

>>> bin(12)
'0b1100'
>>> bin(0)
'0b0'
>>> bin(-1)
'-0b1'

Upvotes: 0

Related Questions