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Crontab Day of the Week syntax
...l
Having two numbers 0 and 7 for Sunday can be useful for writing weekday ranges starting with 0 or ending with 7. So you can write ranges starting with Sunday or ending with it, like 0-2 or 5-7 for example (ranges must start with the lower number and must end with the higher). The abbreviations ca...
Seedable JavaScript random number generator
...ility just use Math.random() and build helper functions around it (eg. randRange(start, end)).
I'm not sure what RNG you're using, but it's best to know and document it so you're aware of its characteristics and limitations.
Like Starkii said, Mersenne Twister is a good PRNG, but it isn't easy to ...
What exceptions should be thrown for invalid or unexpected parameters in .NET?
...
I like to use: ArgumentException, ArgumentNullException, and ArgumentOutOfRangeException.
ArgumentException – Something is wrong with the argument.
ArgumentNullException – Argument is null.
ArgumentOutOfRangeException – I don’t use this one much, but a common use is indexing into a collec...
Getting a list of all subdirectories in the current directory
...der>"
RUNS = 1
def run_os_walk():
a = time.time_ns()
for i in range(RUNS):
fu = [x[0] for x in os.walk(directory)]
print(f"os.walk\t\t\ttook {(time.time_ns() - a) / 1000 / 1000 / RUNS:.0f} ms. Found dirs: {len(fu)}")
def run_glob():
a = time.time_ns()
for i in rang...
Append a NumPy array to a NumPy array
...andom numbers to a 10 X 10 matrix.
myNpArray = np.zeros([1, 10])
for x in range(1,11,1):
randomList = [list(np.random.randint(99, size=10))]
myNpArray = np.vstack((myNpArray, randomList))
myNpArray = myNpArray[1:]
Using np.zeros() an array is created with 1 x 10 zeros.
array([[0., 0., 0....
Redis: possible to expire an element in an array or sorted set?
...d use a timestamp as the score. It's then trivial to delete items by score range, which could be done periodically, or only on every write, with reads always ignoring the out of range elements, by reading only a range of scores.
More here: https://groups.google.com/forum/#!topic/redis-db/rXXMCLNkNS...
Is there a way to do repetitive tasks at intervals?
...xecution) and you do not want to use channels, it's possible to use native range function.
i.e.
package main
import "fmt"
import "time"
func main() {
go heartBeat()
time.Sleep(time.Second * 5)
}
func heartBeat() {
for range time.Tick(time.Second * 1) {
fmt.Println("Foo")
...
Possible to iterate backwards through a foreach?
...n with the List Reverse implementation.
It is possible to reverse certain ranges of a collection too, since Int32.MinValue and Int32.MaxValue are out of the range of any kind of collection index, we can leverage them for the ordering process; if an element index is below the given range, it is assi...
SQL : BETWEEN vs =
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Strange...I think I got confused by the question, the writing of the answer, the comments and the fact that my code obviously has a bug now =)
– xmashallax
Sep 19 '16 at 11:48
...
What is the best way to get all the divisors of a number?
...True:
yield reduce(lambda x, y: x*y, [factors[x][0]**f[x] for x in range(nfactors)], 1)
i = 0
while True:
f[i] += 1
if f[i] <= factors[i][1]:
break
f[i] = 0
i += 1
if i >= nfactors:
...