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How do you get the logical xor of two variables in Python?
How do you get the logical xor of two variables in Python?
24 Answers
24
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What does the caret operator (^) in Python do?
...
It's a bitwise XOR (exclusive OR).
It results to true if one (and only one) of the operands (evaluates to) true.
To demonstrate:
>>> 0^0
0
>>> 1^1
0
>>> 1^0
1
>>> 0^1
1
To explain one of your own exa...
Why can't (or doesn't) the compiler optimize a predictable addition loop into a multiplication?
... test esi, esi
jle .LBB0_1
mov r9d, esi
xor r8d, r8d
xor esi, esi
xor eax, eax
.LBB0_4: # =>This Inner Loop Header: Depth=1
movsxd rdx, dword ptr [rdi + 4*rsi]
imul rcx, rdx, 100000
...
How to toggle a value in Python
...5
>>> x = total - x # toggle
>>> x
3
Solution using XOR
If the value toggles between 0 and 1, you can use a bitwise exclusive-or:
>>> x = 1
>>> x ^= 1
>>> x
0
>>> x ^= 1
>>> x
1
The technique generalizes to any pair of integers....
How is a CRC32 checksum calculated?
...e CRC-32 as a series of "Binary Arithmetic with No Carries", or basically "XOR and shift operations". This is technically called Polynomial Arithmetic.
CRC primer, Chapter 5
To better understand it, think of this multiplication:
(x^3 + x^2 + x^0)(x^3 + x^1 + x^0)
= (x^6 + x^4 + x^3
+ x^5 + x^3...
How does this milw0rm heap spraying exploit work?
...add edx,esp
00000019 07 pop es
0000001A 67305CFF xor [si-0x1],bl
0000001E 98 cwde
0000001F BBD7FFA4FE mov ebx,0xfea4ffd7
00000024 9B wait
00000025 74AD jz 0xffffffd4
00000027 058B8B028D add eax,0x8d028b8b
0000002...
What is the purpose of XORing a register with itself? [duplicate]
xor eax, eax will always set eax to zero, right? So, why does MSVC++ sometimes put it in my executable's code? Is it more efficient that mov eax, 0 ?
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What does the ^ operator do in Java?
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The ^ operator in Java
^ in Java is the exclusive-or ("xor") operator.
Let's take 5^6 as example:
(decimal) (binary)
5 = 101
6 = 110
------------------ xor
3 = 011
This the truth table for bitwise (JLS 15.22.1) and logical (JLS 15.22.2) xor:
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What is Bit Masking?
...ue
Bitwise ORing in order to set a subset of the bits in the value
Bitwise XORing in order to toggle a subset of the bits in the value
Below is an example of extracting a subset of the bits in the value:
Mask: 00001111b
Value: 01010101b
Applying the mask to the value means that we want to cl...
What does (x ^ 0x1) != 0 mean?
...
The XOR operation (x ^ 0x1) inverts bit 0. So the expression effectively means: if bit 0 of x is 0, or any other bit of x is 1, then the expression is true.
Conversely the expression is false if x == 1.
So the test is the same ...