Python program for decimal to binary conversion

September 29, 2022

Decimal to binary conversion in Python

Here, in this page we will discuss the program for Decimal to binary conversion in python. A decimal number is a standard representation of integers or non-integers, decimal numbers are also called as numbers with base 10. Whereas in binary number system numbers are with base 10 and shows representation by 0 and 1.

Decimal to binary conversion

Methods discussed

  • Method 1: Binary Bits stored in Array
  • Method 2: Using mathematical operations to generate binary equivalent.

Algorithm  ( Method 1 )

  • Initialize a empty array as binaryArray
  • while input number is greater then 0
  • Append 1 if unit digit of num is odd else append 0
  • Assign half the value of num to num
  • Print all the values of  binaryArray

Python Code

Run 
def convertBinary(num):
    binaryArray = []
    while num>0:
        binaryArray.append(num%2)
        num = num//2
    for j in binaryArray:
        print(j, end="")


decimal_num = 21
convertBinary(decimal_num)

Output

Binary of 21 is : 10101

Octal to Decimal conversion

Hexadecimal to Decimal conversion

Decimal to Binary conversion

Decimal to Octal Conversion

Decimal to Hexadecimal Conversion

Binary to Octal conversion

Algorithm  ( Method 2 )

  • Initialize variables binary, i, rem and assign 0, 1, 0 respectively
  • While input number is greater then zero run he loop
  • rem equals to divisibility of input by 2
  • num equals to half of num
  • Add rem * i to binary
  • Multiply i by 10
  • return binary  

Python Code

Run 
def convertBinary(num):
    binary = 0
    i, rem = 1, 0
    while num != 0:
        rem = num % 2
        num = num // 2
        binary += rem * i
        i *= 10
    return binary


decimal_num = 21
print("Binary of", decimal_num, "is : ", end="")
print(convertBinary(decimal_num))

Output

Binary of 21 is : 10101

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10 comments on “Python program for decimal to binary conversion”


  • Mathavan

    num = int(input(“Enter a Decimal number: “))
    x = num
    s = 0
    l = []
    m = []
    while x > 0:
    t = x % 2
    l.append(t)
    num = num // 2
    x = x // 2
    m = (l[::-1])
    for i in m:
    print(i, end=””)


  • Instan

    num = int(input(“Enter a Decimal number: “))
    x = num
    s = 0
    l = []
    m = []
    while x > 0:
    t = x % 2
    l.append(t)
    num = num // 2
    x = x // 2
    m = (l[::-1])
    for i in m:
    print(i, end=””)


  • priyarajswarnakar2018

    Follow this:-
    def decimaltoBinary(num):
    arr=[]
    while num>0:
    a=num%2
    arr.append(a)
    num=num//2

    arr=arr[::-1]
    for i in arr:
    print(i,end=””)

    num=int(input())
    decimaltoBinary(num)


  • Bharath

    without built in function:
    d=int(input())
    b=”
    i=0
    while(d!=0):
    r=d%2
    s=str(r)
    b+=s
    d=d//2
    i+=1
    print(b[::-1])


  • thedashinganon

    n = int(input(“Enter Decimal Number : “))
    res = 0
    i = 1
    while (n!=0):
    rem = n % 2
    res = res + rem * i
    n= n//2
    i = i*10
    pre = ‘0b’
    print(“Binary Value is “,(pre+str(res)))


  • Sonal

    num=int(input(“Enter the decimal number “))
    sum=0
    temp=num
    base=1
    while(temp):
    digit=temp%2
    sum+=digit*base
    base*=10
    temp//=2
    print(“The binary value of {} is {}”.format(num,sum))


  • Abhishek

    a=int(input(“Enter the number :”))
    c=[]
    def decimal(n):
    b=n%2
    d=n//2
    c.append(b)
    if(d==0):
    for i in c[::-1]:
    print(i,end=””)
    else:
    decimal(d)

    b=decimal(a)