Bitwise operators in Python allow you to perform operations at the bit level. These operators are essential for tasks such as low-level programming, cryptography, and working with hardware. In this guide, we will explore all Python bitwise operators with clear examples to help you master their usage.
1. What Are Bitwise Operators?
Bitwise operators work on binary representations of numbers (bits). These operators directly manipulate the bits and return results based on bitwise operations. Python provides the following bitwise operators:
| Operator | Name | Description | |||
|---|---|---|---|---|---|
& | Bitwise AND | Sets each bit to 1 if both bits are 1 | |||
| | | Bitwise OR |
| |||
^ | Bitwise XOR | Sets each bit to 1 if only one bit is 1 | |||
~ | Bitwise NOT | Inverts all the bits | |||
<< | Left Shift | Shifts bits to the left | |||
>> | Right Shift | Shifts bits to the right |
2. Understanding Binary Representation
Before diving into examples, it is crucial to understand how numbers are represented in binary.
For example:
5in binary is01013in binary is0011
3. **Bitwise AND (&)
The & operator compares each bit of two numbers. A bit is set to 1 if both corresponding bits are 1.
Syntax:
result = a & bExample:
a = 5 # Binary: 0101
b = 3 # Binary: 0011
result = a & b # Binary: 0001
print(result) # Output: 1Truth Table:
| Bit 1 | Bit 2 | Result |
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
4. **Bitwise OR (|)
The | operator compares each bit of two numbers. A bit is set to 1 if at least one of the corresponding bits is 1.
Syntax:
result = a | bExample:
a = 5 # Binary: 0101
b = 3 # Binary: 0011
result = a | b # Binary: 0111
print(result) # Output: 7Truth Table:
| Bit 1 | Bit 2 | Result |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
5. **Bitwise XOR (^)
The ^ operator compares each bit of two numbers. A bit is set to 1 if the corresponding bits are different.
Syntax:
result = a ^ bExample:
a = 5 # Binary: 0101
b = 3 # Binary: 0011
result = a ^ b # Binary: 0110
print(result) # Output: 6Truth Table:
| Bit 1 | Bit 2 | Result |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
6. **Bitwise NOT (~)
The ~ operator inverts all the bits of a number. For positive numbers, it returns the negative value of the number minus one.
Syntax:
result = ~aExample:
a = 5 # Binary: 0101
result = ~a # Binary: -0110
print(result) # Output: -6Explanation:
In binary, ~5 flips all bits of 0101 to 1010. In two's complement representation, this corresponds to -6.
7. **Left Shift (<<)
The << operator shifts the bits of a number to the left by the specified number of positions. Each left shift doubles the number.
Syntax:
result = a << nExample:
a = 5 # Binary: 0101
result = a << 2 # Binary: 10100
print(result) # Output: 20Explanation:
Shifting 0101 two places to the left gives 10100, which is 20 in decimal.
8. **Right Shift (>>)
The >> operator shifts the bits of a number to the right by the specified number of positions. Each right shift divides the number by two (ignoring the remainder).
Syntax:
result = a >> nExample:
a = 5 # Binary: 0101
result = a >> 2 # Binary: 0001
print(result) # Output: 1Explanation:
Shifting 0101 two places to the right gives 0001, which is 1 in decimal.
9. Combining Bitwise Operators
You can combine bitwise operators to perform complex bit-level operations.
Example:
a = 5 # Binary: 0101
b = 3 # Binary: 0011
# Combining operators
result = (a & b) | (~a)
print(result) # Output: -210. Practical Applications of Bitwise Operators
1. Setting and Clearing Bits
# Setting a bit
number = 0b1010
position = 1
number |= (1 << position)
print(bin(number)) # Output: 0b1011
# Clearing a bit
number &= ~(1 << position)
print(bin(number)) # Output: 0b10102. Checking if a Bit is Set
number = 0b1010
position = 2
is_set = (number & (1 << position)) != 0
print(is_set) # Output: True3. Swapping Two Numbers Without a Temporary Variable
a = 5
b = 3
a = a ^ b
b = a ^ b
a = a ^ b
print(a, b) # Output: 3, 511. Common Mistakes with Bitwise Operators
Mistake 1: Confusing Bitwise Operators with Logical Operators
a = 5
b = 3
# Incorrect: Using 'and' instead of '&'
result = a and b # Logical AND, not Bitwise AND
print(result) # Output: 3Mistake 2: Ignoring Operator Precedence
result = ~a & b # Not the same as ~(a & b)Use parentheses to make the precedence clear.
Conclusion
Bitwise operators are powerful tools in Python for performing low-level operations. They are invaluable in fields like cryptography, network programming, and embedded systems. By mastering these operators, you can write more efficient and optimized code.
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