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Javascript shorthand ternary operator
...g for, where it defaults if undefined?
var foo = bar || 1; // 1
var bar = 2;
foo = bar || 1; // 2
By the way, this works for a lot of scenarios, including objects:
var foo = bar || {}; // secure an object is assigned when bar is absent
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Numpy argsort - what is it doing?
... to the documentation
Returns the indices that would sort an array.
2 is the index of 0.0.
3 is the index of 0.1.
1 is the index of 1.41.
0 is the index of 1.48.
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How do I get the row count of a pandas DataFrame?
...setup=lambda n: pd.DataFrame(np.arange(n * 3).reshape(n, 3)),
n_range=[2**k for k in range(25)],
kernels=[
lambda data: data.shape[0],
lambda data: data[0].count(),
lambda data: len(data.index),
],
labels=["data.shape[0]", "data[0].count()", "len(data.index)"]...
How to convert Java String into byte[]?
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edited Mar 31 '16 at 21:54
answered Sep 2 '13 at 10:46
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Disable a group of tests in rspec?
... in the output:
before { skip("Awaiting a fix in the gem") }
with RSpec 2:
before { pending }
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Join a list of items with different types as string in Python
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answered Aug 28 '10 at 9:09
Mark ByersMark Byers
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Can you have if-then-else logic in SQL? [duplicate]
...e1 WHERE project = 1
ELSE IF ((SELECT COUNT(*) FROM table1 WHERE project = 2) > 0)
SELECT product, price FROM table1 WHERE project = 2
ELSE IF ((SELECT COUNT(*) FROM table1 WHERE project = 3) > 0)
SELECT product, price FROM table1 WHERE project = 3
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Why should hash functions use a prime number modulus?
...ong time ago, I bought a data structures book off the bargain table for $1.25. In it, the explanation for a hashing function said that it should ultimately mod by a prime number because of "the nature of math".
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Get the first element of each tuple in a list in Python [duplicate]
...[x[0] for x in rows]
Below is a demonstration:
>>> rows = [(1, 2), (3, 4), (5, 6)]
>>> [x[0] for x in rows]
[1, 3, 5]
>>>
Alternately, you could use unpacking instead of x[0]:
res_list = [x for x,_ in rows]
Below is a demonstration:
>>> lst = [(1, 2), (...