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# 191. Number of 1 Bits

## Question 191

<https://leetcode.com/problems/number-of-1-bits/description/>

Write a function that takes an unsigned integer and returns the number of '1' bits it has (also known as the [Hamming weight](http://en.wikipedia.org/wiki/Hamming_weight)).

**Example 1:**

```
Input: 11
Output: 3
Explanation: Integer 11 has binary representation 00000000000000000000000000001011 
```

### Answer&#x20;

```python
class Solution(object):
    def hammingWeight(self, n):
        AnswerINT = 0
        while(n):
            if(n%2):
                AnswerINT += 1
            n = n // 2
        return AnswerINT
```