storing negative value in mysql
Use MySQL DECIMAL type? Standard SQL requires that DECIMAL(5,2) be able to store any value with five digits and two decimals, so values that can be stored in the salary column range from -999.99 to 999.99
negative-number
Python Argparse: Issue with optional arguments which are negative numbers
One workaround I’ve found is to quote the value, but adding a space. That is, ./blaa.py –xlim ” -2.e-3″ 1e4 This way argparse won’t think -2.e-3 is an option name because the first character is not a hyphen-dash, but it will still be converted properly to a float because float(string) ignores spaces on the left.
Why is the sign different after subtracting unsigned and signed?
Let’s start by analysing the result of t – d. t is an unsigned int while d is an int, so to do arithmetic on them, the value of d is converted to an unsigned int (C++ rules say unsigned gets preference here). So we get 10u – 16u, which (assuming 32-bit int) wraps around … Read more
how to convert negative integer value to hex in python
Python’s integers can grow arbitrarily large. In order to compute the raw two’s-complement the way you want it, you would need to specify the desired bit width. Your example shows -199703103 in 64-bit two’s complement, but it just as well could have been 32-bit or 128-bit, resulting in a different number of 0xf‘s at the … Read more
How to change a negative number to zero in python without using decision structures
Can you use built-in functions? Because this is normally done using: max(0, points)
Right shifting negative numbers in C
It looks like your implementation is probably doing an arithmetic bit shift with two’s complement numbers. In this system, it shifts all of the bits to the right and then fills in the upper bits with a copy of whatever the last bit was. So for your example, treating int as 32-bits here: nPosVal = … Read more
How does the modulo (%) operator work on negative numbers in Python?
Unlike C or C++, Python’s modulo operator (%) always return a number having the same sign as the denominator (divisor). Your expression yields 3 because (-5) / 4 = -1.25 –> floor(-1.25) = -2 (-5) % 4 = (-2 × 4 + 3) % 4 = 3. It is chosen over the C behavior because … Read more
HashCode giving negative values
I don’t think hash values should be negative. Why not? It’s entirely valid to have negative hash codes. Most ways of coming up with a hash code naturally end up with negative values, and anything dealing with them should take account of this. However, I’d consider a different approach to coming up with your hash … Read more
In Python, what is a good way to round towards zero in integer division?
Do floating point division then convert to an int. No extra modules needed. Python 3: >>> int(-1 / 2) 0 >>> int(-3 / 2) -1 >>> int(1 / 2) 0 >>> int(3 / 2) 1 Python 2: >>> int(float(-1) / 2) 0 >>> int(float(-3) / 2) -1 >>> int(float(1) / 2) 0 >>> int(float(3) / … Read more
Are there any non-twos-complement implementations of C?
The most recent example I can find is the UNISYS 2200 series, based on UNIVAC, with ones-complement arithmetic. The various models were produced between 1986 and 1997 but the OS was still in active development as late as 2015. They also had a C compiler, as seen here. It seems likely that they may still … Read more