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What is a lambda expression in C++11?
What is a lambda expression in C++11? When would I use one? What class of problem do they solve that wasn't possible prior to their introduction?
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Generate all permutations of a list without adjacent equal elements
...lgorithm returns optimal solutions, by the following logic. We call a prefix (partial solution) safe if it extends to an optimal solution. Clearly the empty prefix is safe, and if a safe prefix is a whole solution then that solution is optimal. It suffices to show inductively that each greedy step m...
Optional Parameters with C++ Macros
...e to a bug in the MSVC compiler which they have acknowledged but haven't fixed in nearly a decade. However, workarounds are available.
– BeeOnRope
Nov 22 '17 at 19:45
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GroupBy pandas DataFrame and select most common value
...: ['NY','New','Spb','NY']})
source.groupby(['Country','City']).agg(lambda x:x.value_counts().index[0])
In case you are wondering about performing other agg functions in the .agg()
try this.
# Let's add a new col, account
source['account'] = [1,2,3,3]
source.groupby(['Country','City']).agg(mod ...
How to document class attributes in Python? [closed]
...lass attributes, or any sort of attributes, for that matter. What is the expected and supported way, should there be one, to document these attributes? Currently I'm doing this sort of thing:
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Is there a better way to iterate over two lists, getting one element from each list for each iterati
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In Python 2.x you might consider itertools.izip instead (zip does the same thing in Python 3.x).
– Nicholas Riley
Dec 17 '09 at 2:08
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Go > operators
Could someone please explain to me the usage of << and >> in Go? I guess it is similar to some other languages.
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Check if a number is int or float
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Use isinstance.
>>> x = 12
>>> isinstance(x, int)
True
>>> y = 12.0
>>> isinstance(y, float)
True
So:
>>> if isinstance(x, int):
print 'x is a int!'
x is a int!
_EDIT:_
As pointed out, in case o...
Element-wise addition of 2 lists?
... list2) )
[5, 7, 9]
or zip with a list comprehension:
>>> [sum(x) for x in zip(list1, list2)]
[5, 7, 9]
Timing comparisons:
>>> list2 = [4, 5, 6]*10**5
>>> list1 = [1, 2, 3]*10**5
>>> %timeit from operator import add;map(add, list1, list2)
10 loops, best of ...