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Real world use cases of bitwise operators [closed]
(41 answers)
Bitwise operation and usage
(17 answers)
Closed 12 months ago.
I understand that the bitwise and operator (&) is equivalent to a product of two bit values. When would I use it?
Please also help me understand what num&1 does in the code below:
def func(num):
n = 1 + func((3*num+1) if num&1 else (num>>1))
return n
As the comments mentioned, num&1 is a bitwise AND between num and 1.
Since 1 in binary is ...000000001, the AND will result True iff the least significant bit of num is 1, in other words, if it is odd (here some explanation of binary)
Related
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The tilde operator in Python
(9 answers)
Closed 1 year ago.
pd_selftest = pd_selftest[pd_selftest['SICCD'] != 0]
pd_selftest = pd_selftest[~pd_selftest['SICCD'].isnull()]
I'd like to know what the function of the ~ is in the above code.
That's the bit-wise invert or not operator. So, it returns only those lines where the SICCID column is not null. I would probably use the word not in this case.
This question already has answers here:
Why is exponentiation applied right to left?
(4 answers)
Closed 2 years ago.
print (2**3**2)
Answer is 512.
Why 512 is answer not 64? Because ((2^3)^2) = 64
I want to know the inside math operation of print (2** 3**2)
The order of operations for exponentiation is right-to-left, not-left-to right. So:
2**3**2
is interpretted as:
2**(3**2) = 2**(9) = 512
This question already has answers here:
What does the ^ (XOR) operator do? [duplicate]
(6 answers)
Closed 2 years ago.
Shouldn't it be 8?
The same thing goes with 3 ^ 2. I also got 1.
This is confusing...
In Python, ^ is a bitwise XOR operator. I believe what you're looking for is the exponent operator, **. An example would be 2**3 which outputs 8, like I believe you were looking for.
The ^ operator does a bitwise XOR operation. In python to do power calculation use pow() function:
pow(3,2)
Or use **
3**2
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Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
(3 answers)
Closed 2 years ago.
Why "~False" is -1 in Python?
I was using a boolean variable in Python. When I try to do not of that, it returns -1. I want to understand why so? why a variable a changing its data-type duo to this operation.
Trying to add more details
b0 = False
print(type(b0))
b0 = ~b0
print(type(b0))
>>bool
>>int
The tilde ~ is the bitwise 'not' operator, not the boolean 'not' operator. To do a not you probably want 'not False'.
The reason for it changing its data type is that it treats False as binary 0 and then flips it to -1.
This question already has answers here:
and / or operators return value [duplicate]
(4 answers)
Closed 6 years ago.
This looks like a short circuit way of writing code but I just can't understand it. Is there a specific way to read this kind of short circuit.
e.g:
n = n and int(n)
n = n or int(n)
and conditions return the last truthy value or the first falsy one. So if n is falsy, n will remain whatever value it was. If n is truthy, it will be cast to an int.