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Is it worth using Python's re.compile?
...uick glance at the actual Python 2.5 library code, I see that Python internally compiles AND CACHES regexes whenever you use them anyway (including calls to re.match()), so you're really only changing WHEN the regex gets compiled, and shouldn't be saving much time at all - only the time it takes to ...
How can I count the occurrences of a list item?
...1, 4, 1].count(1)
3
Don't use this if you want to count multiple items. Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance. If you want to count all items, or even just multiple items, use Counter, as explained in the othe...
How to make lists contain only distinct element in Python? [duplicate]
...ving
return list(_f(seq, idfun))
def _f(seq, idfun=None):
''' Originally proposed by Andrew Dalke '''
seen = set()
if idfun is None:
for x in seq:
if x not in seen:
seen.add(x)
yield x
else:
for x in seq:
x = idfun(x)
if x not in seen:
s...
How do I initialize the base (super) class?
... and invoke their base class through super(), e.g.
class X(object):
def __init__(self, x):
pass
def doit(self, bar):
pass
class Y(X):
def __init__(self):
super(Y, self).__init__(123)
def doit(self, foo):
return super(Y, self).doit(foo)
Because python knows about old- an...
multiprocessing.Pool: When to use apply, apply_async or map?
...
Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:
apply(f,args,kwargs)
apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,
f(*args,**kwargs)
is preferred. The...
What is the purpose of the single underscore “_” variable in Python?
...cate that part
of a function result is being deliberately ignored (Conceptually, it is being discarded.), as in code like:
label, has_label, _ = text.partition(':').
As part of a function definition (using either def or lambda), where
the signature is fixed (e.g. by a callback or parent class API), ...
How do I choose grid and block dimensions for CUDA kernels?
...eads per block should be a round multiple of the warp size, which is 32 on all current hardware.
Each streaming multiprocessor unit on the GPU must have enough active warps to sufficiently hide all of the different memory and instruction pipeline latency of the architecture and achieve maximum throu...
What are best practices for validating email addresses on iOS 2.0
... ; "]", or "\"
Yes, that means +, ', etc are all legit.
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Convert decimal to binary in python [duplicate]
...
all numbers are stored in binary. if you want a textual representation of a given number in binary, use bin(i)
>>> bin(10)
'0b1010'
>>> 0b1010
10
...
'is' versus try cast with null check
...ing)
{
var x = (string) o;
}
This translates to the following IL:
IL_0000: nop
IL_0001: ldstr "test"
IL_0006: stloc.0 // o
IL_0007: ldloc.0 // o
IL_0008: isinst System.String
IL_000D: ldnull
IL_000E: cgt.un
IL_0010: stloc.1
IL_0011: ldloc....