Binary to decimal and vice-versa in Python

In this article, we will see how to convert Binary to Decimal and Decimal to Binary. Binary is the simplest kind of number system that uses only two digits of 0 and 1 (i.e. value of base 2). Since digital electronics have only these two states (either 0 or 1), so binary number is most preferred in modern computer engineer, networking and communication specialists, and other professionals.

Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represent units, tens, hundreds, thousands, and so on.

Let’s say the following is our Binary −

1111

The output is the following Decimal −

15

Let’s say the following is our Decimal −

20

The output is the following Binary −

10100

Decimal To Binary Conversion in Python

In this example, we will convert Decimal to Binary −

Example

s = 0
i = 1
myDec = 18

print("Decimal = ",myDec)
# Loop through
while myDec>0:
	rem = int(myDec%2)
	s = s+(i*rem)
	myDec = int(myDec/2)
	i = i*10
	
print ("The binary of the given number = ",s)

Output

Decimal = 18
The binary of the given number = 10010

Binary To Decimal Conversion in Python

In this example, we will convert Binary to Decimal −

Example

s = 0
i = 1
myBin = "1101"

print("Binary = ",myBin)

n=len(myBin)
res=0

for i in range(1,n+1):
	res = res+ int(myBin[i-1])*2**(n-i)
print ("The decimal of the given binary = ",res)

Output

Binary = 1101
The decimal of the given binary = 13