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Why doesn't list have safe “get” method like dictionary?
...f your list).
Of course, you can easily implement this yourself:
def safe_list_get (l, idx, default):
try:
return l[idx]
except IndexError:
return default
You could even monkeypatch it onto the __builtins__.list constructor in __main__, but that would be a less pervasive change since...
Asynchronous method call in Python?
...an use pools of processes and then get results asynchronously with:
apply_async(func[, args[, kwds[, callback]]])
E.g.:
from multiprocessing import Pool
def f(x):
return x*x
if __name__ == '__main__':
pool = Pool(processes=1) # Start a worker processes.
result = pool....
How to pick just one item from a generator?
...ption if necessary, or use the default argument to next():
next(g, default_value)
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How to log a method's execution time exactly in milliseconds?
...
I just compared NSDate and mach_absolute_time() at around 30ms level. 27 vs. 29, 36 vs. 39, 43 vs. 45. NSDate was easier to use for me and the results were similar enough not to bother with mach_absolute_time().
– nevan king
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Should I use 'has_key()' or 'in' on Python dicts?
...
in is definitely more pythonic.
In fact has_key() was removed in Python 3.x.
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Get last result in interactive Python shell
...
Underscore.
>>> 5+5
10
>>> _
10
>>> _ + 5
15
>>> _
15
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Is gcc 4.8 or earlier buggy about regular expressions?
....
Seriously though, who though that shipping an implementation of regex_search that only does "return false" was a good idea?
It wasn't such a bad idea a few years ago, when C++0x was still a work in progress and we shipped lots of partial implementations. No-one thought it would remain unusab...
Average of 3 long integers
...ng divide by constants technique from hacker's delight
public class int128_t {
private int H;
private long L;
public int128_t(int h, long l)
{
H = h;
L = l;
}
public int128_t add(int128_t a)
{
int128_t s;
s.L = L + a.L;
s.H = H +...
Is there a range class in C++11 for use with range based for loops?
...C++ standard library does not have one, but Boost.Range has boost::counting_range, which certainly qualifies. You could also use boost::irange, which is a bit more focused in scope.
C++20's range library will allow you to do this via view::iota(start, end).
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How to merge lists into a list of tuples?
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In Python 2:
>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> zip(list_a, list_b)
[(1, 5), (2, 6), (3, 7), (4, 8)]
In Python 3:
>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> list(zi...