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Python multiprocessing PicklingError: Can't pickle
...ol(processes=5)
# asyn execution of lambda
jobs = []
for i in range(10):
job = apply_async(pool, lambda a, b: (a, b, a * b), (i, i + 1))
jobs.append(job)
for job in jobs:
print job.get()
print
# async execution of static method
class O(object):...
Are Javascript arrays sparse?
...s like reduce(), Math.max(), and "for ... of" will walk through the entire range of possible integer indices form 0 to the length, visiting many that return 'undefined'. BUT 'for ... in' loops might do as you expect, visiting only the defined keys.
Here's an example using Node.js:
"use strict";
c...
C++ map access discards qualifiers (const)
...) for std::map. If element doesn't exist the function throws a std::out_of_range exception, in contrast to operator [].
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best way to preserve numpy arrays on disk
...Not that random data
data['semi-random'] = np.zeros((size, size))
for i in range(size):
for j in range(size):
data['semi-random'][i,j] = np.sum(data['random'][i,:]) + np.sum(data['random'][:,j])
# Not random data
data['not-random'] = np.arange( size*size, dtype=np.float64 ).reshape( (si...
Concatenating two one-dimensional NumPy arrays
...
],
labels=["r_", "stack+reshape", "hstack", "concatenate"],
n_range=[2 ** k for k in range(19)],
xlabel="len(a)",
)
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When should I use perror(“…”) and fprintf(stderr, “…”)?
...For example, strtol will return LONG_MAX or LONG_MIN if a string is out of range and set errno to ERANGE. So if strtol fails due to out of range, I would use perror.
– freeboy1015
Aug 24 '12 at 2:22
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Quicksort: Choosing the pivot
...
There are several options.
Simple: Pick the first or last element of the range. (bad on partially sorted input)
Better: Pick the item in the middle of the range. (better on partially sorted input)
However, picking any arbitrary element runs the risk of poorly partitioning the array of size n into...
Should the hash code of null always be zero, in .NET
... example, the hash code of an int is just the int, so it uses the full int range. What value in that range do you choose for null? Whatever one you pick will collide with the value's hash code itself.
Collisions in and of themselves are not necessarily a problem, but you need to know they are there...
Javascript equivalent of Python's zip function
... make this handle any iterable (e.g. in Python you can use zip on strings, ranges, map objects, etc.), you could define the following:
function iterView(iterable) {
// returns an array equivalent to the iterable
}
However if you write zip in the following way, even that won't be necessary:
f...
What is the difference between BIT and TINYINT in MySQL?
...
TINYINT[(M)] [UNSIGNED] [ZEROFILL]
A very small integer. The signed range
is -128 to 127. The unsigned range is
0 to 255.
Additionally consider this;
BOOL, BOOLEAN
These types are synonyms for
TINYINT(1). A value of zero is
considered false. Non-zero values are
considered tru...