Python print bits Python Program to Count Set Bits in a Number

Python print bits: Given a number ,the task is to count the set bits of the given number in its binary representation.

Examples:

Example1:

Input:

given number =235

Output:

The total number of set bits in the given number  235  : 
6

Example2:

Input:

given number =8

Output:

The total number of set bits in the given number  8  : 
1

Example3:

Input:

given number =375

Output:

The total number of set bits in the given number  375  : 
7

Program to Count Set Bits in a Number in Python

There are several ways to count set bits in the binary representation of the given number some of them are:

By checking bit by bit from end using modulus operator
By checking bit by bit from end using & operator
By converting into binary using bin() and using count() function to count set bits
By converting into binary using bin() and using sum() function to count set bits

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Method #1: By checking bit by bit from end using modulus operator

A simple method is to take each bit into consideration in a number (set or unset) and hold an counter to track the set bits.

Approach:

Set the variable say count to 0 to count the total number of set bits.
We utilize the while loop.
We’ll keep going till the number is bigger than zero (Condition of while statement)
Using the % operator, we will determine whether the last check bit is set or not.
If the check bit is 1, it indicates that the bit is set, and we increment the count.
Divide the given number by 2.
Print the count.

Below is the implementation:

def countSetBit(numb):
    # checking if the given number is greater than 1
    if numb > 1:
      # Set the variable say setbitcount to 0 to count the total number of set bits.
        setbitcount = 0
        # looping till number greater than 0 using while loop
        while(numb > 0):
            # We will get the last check bit whether it is set bit or not using % operator
            checkbit = numb % 2
            # checking if the check bit is 1 or not
            # if the check bit is 1 then increment the setbitcount
            if(checkbit == 1):
                setbitcount = setbitcount+1
            # divide the number by 2
            numb = numb//2
    # return the setbitcount
    return setbitcount


# Driver code
given_numb = 235
# passing given number to countSetBit function to
# count the total number of set bits in the given number
print("The total number of set bits in the given number ", given_numb, " : ")
print(countSetBit(given_numb))

Output:

The total number of set bits in the given number  235  : 
6

Method #2: By checking bit by bit from end using & operator

A simple method is to take each bit into consideration in a number (set or unset) and hold an counter to track the set bits.

Approach:

Set the variable say count to 0 to count the total number of set bits.
We utilize the while loop.
We’ll keep going till the number is bigger than zero (Condition of while statement)
Using the & operator, we will determine whether the last check bit is set or not.
If the check bit is 1, it indicates that the bit is set, and we increment the count.
Divide the given number by 2.
Print the count.

We use n&1 to check whether it is set bit or not.

Below is the implementation:

def countSetBit(numb):
    # checking if the given number is greater than 1
    if numb > 1:
      # Set the variable say setbitcount to 0 to count the total number of set bits.
        setbitcount = 0
        # looping till number greater than 0 using while loop
        while(numb > 0):
            # We will get the last check bit whether it is set bit or not using & operator
            # checking if the check bit is 1 or not
            # if the check bit is 1 then increment the setbitcount
            if(numb & 1):
                setbitcount = setbitcount+1
            # divide the number by 2
            numb = numb//2
    # return the setbitcount
    return setbitcount


# Driver code
given_numb = 235
# passing given number to countSetBit function to
# count the total number of set bits in the given number
print("The total number of set bits in the given number ", given_numb, " : ")
print(countSetBit(given_numb))

Output:

The total number of set bits in the given number  235  : 
6

Method #3: By converting into binary using bin() and using count() function to count set bits

Approach:

First we convert the given number into binary using bin() function.
Then we count total number of ‘1’s in the binary string using count() function
Print the count

Below is the implementation:

def countSetBit(numb):
    # converting given number to binary reepresentatioon using bin()
    binNum = bin(numb)
    # we count total number of '1's in the binary string using count() function
    setbitcount = binNum.count('1')
    # return the setbitcount
    return setbitcount


# Driver code
given_numb = 235
# passing given number to countSetBit function to
# count the total number of set bits in the given number
print("The total number of set bits in the given number ", given_numb, " : ")
print(countSetBit(given_numb))

Output:

The total number of set bits in the given number  235  : 
6

Method #4: By converting into binary using bin() and using sum() function to count set bits

Approach:

First we convert the given number into binary using bin() function.
We slice from 2 to end of the binary string using slicing (to remove 0b characters from binary string)
Convert every character of binary string to integer using map and then convert it to list
Then we count total number of ‘1’s in the binary string list using sum() function(because the binary string contains only 0 and 1)
Print the count

Below is the implementation:

def countSetBit(numb):
    # converting given number to binary reepresentatioon using bin()
    binNum = bin(numb)
    # We will slice from 2 index to last index of the result returned by binary string
    binNum = binNum[2:]
    # Convert every character of binary string to integer using map
    # and then convert it to list
    binList = list(map(int, binNum))
    # we count total number of '1's in the binary string using sum() function
    setbitcount = sum(binList)
    # return the setbitcount
    return setbitcount


# Driver code
given_numb = 235
# passing given number to countSetBit function to
# count the total number of set bits in the given number
print("The total number of set bits in the given number ", given_numb, " : ")
print(countSetBit(given_numb))

Output:

The total number of set bits in the given number  235  : 
6

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