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sqlalchemy unique across multiple columns
... declares those in the table definition, or if using declarative as in the __table_args__:
# version1: table definition
mytable = Table('mytable', meta,
# ...
Column('customer_id', Integer, ForeignKey('customers.customer_id')),
Column('location_code', Unicode(10)),
UniqueConstraint...
What does the restrict keyword mean in C++?
...h the time.
Edit
I also found that IBM's AIX C/C++ compiler supports the __restrict__ keyword.
g++ also seems to support this as the following program compiles cleanly on g++:
#include <stdio.h>
int foo(int * __restrict__ a, int * __restrict__ b) {
return *a + *b;
}
int main(void) {
...
What is the best way to compute trending topics or tags?
...wing code demonstrates this.
from math import sqrt
class zscore:
def __init__(self, pop = []):
self.number = float(len(pop))
self.total = sum(pop)
self.sqrTotal = sum(x ** 2 for x in pop)
def update(self, value):
self.number += 1.0
self.total += valu...
What are good uses for Python3's “Function Annotations”
...re what you make of them.
They can be used for documentation:
def kinetic_energy(mass: 'in kilograms', velocity: 'in meters per second'):
...
They can be used for pre-condition checking:
def validate(func, locals):
for var, test in func.__annotations__.items():
value = locals[v...
Re-raise exception with a different type and message, preserving existing information
...ble to whatever code catches the new exception.
By using this feature, the __cause__ attribute is set. The built-in exception handler also knows how to report the exception's “cause” and “context” along with the traceback.
In Python 2, it appears this use case has no good answer (as describ...
What does extern inline do?
... I'd like to add that for Microsoft's Visual C++, there's a __forceinline keyword that will enforce your function getting inlined. This is obviously a compiler-specific extension only for VC++.
– untitled8468927
Jan 17 '14 at 12:12
...
In Python, how do I indicate I'm overriding a method?
...an think of a better solution please post it here!
def overrides(interface_class):
def overrider(method):
assert(method.__name__ in dir(interface_class))
return method
return overrider
It works as follows:
class MySuperInterface(object):
def my_method(self):
p...
Why is `std::move` named `std::move`?
...
template <class T>
void
swap(T& a, T& b)
{
T tmp(static_cast<T&&>(a));
a = static_cast<T&&>(b);
b = static_cast<T&&>(tmp);
}
One has to recall that at this point in history, the only thing that "&&" could possibly mean w...
Bulk insert with SQLAlchemy ORM
... = [
User(name="u1"),
User(name="u2"),
User(name="u3")
]
s.bulk_save_objects(objects)
s.commit()
Here, a bulk insert will be made.
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Convert Base64 string to an image file? [duplicate]
... data in the function before decoding the string, like so.
function base64_to_jpeg($base64_string, $output_file) {
// open the output file for writing
$ifp = fopen( $output_file, 'wb' );
// split the string on commas
// $data[ 0 ] == "data:image/png;base64"
// $data[ 1 ] == &l...