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Why are C# 4 optional parameters defined on interface not enforced on implementing class?
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answered Feb 7 '11 at 16:23
Eric LippertEric Lippert
599k164164 gold badges11551155 silver badges20142014 bronze badges
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How to check if an element is in an array
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Swift 2, 3, 4, 5:
let elements = [1, 2, 3, 4, 5]
if elements.contains(5) {
print("yes")
}
contains() is a protocol extension method of SequenceType (for sequences of Equatable elements) and not a global method as in
earlier rel...
What is Android keystore file, and what is it used for?
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132
The answer I would provide is that a keystore file is to authenticate yourself to anyone who is...
What's invokedynamic and how do I use it?
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answered Jul 10 '11 at 2:23
Ernest Friedman-HillErnest Friedman-Hill
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How to convert an array of strings to an array of floats in numpy?
... list_of_strings)) (or equivalently, use a list comprehension). (In Python 3, you'll need to call list on the map return value if you use map, since map returns an iterator now.)
However, if it's already a numpy array of strings, there's a better way. Use astype().
import numpy as np
x = np.array...
How to check whether a string is Base64 encoded or not
... if a string is base64 encoded or not:
^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$
In base64 encoding, the character set is [A-Z, a-z, 0-9, and + /]. If the rest length is less than 4, the string is padded with '=' characters.
^([A-Za-z0-9+/]{4})* means the string starts with 0 ...
Do python projects need a MANIFEST.in, and what should be in it?
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answered Jul 13 '14 at 23:28
Jan VlcinskyJan Vlcinsky
36.2k1111 gold badges8383 silver badges8484 bronze badges
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Oracle “Partition By” Keyword
...ry record in the emp table.)
emp_no dept_no DEPT_COUNT
1 10 3
2 10 3
3 10 3 <- three because there are three "dept_no = 10" records
4 20 2
5 20 2 <- two because there are two "dept_no = 20" records
If there was another column (e....
Iterate through pairs of items in a Python list [duplicate]
...ls import tee
def pairwise(iterable):
"s -> (s0,s1), (s1,s2), (s2, s3), ..."
a, b = tee(iterable)
next(b, None)
return zip(a, b)
for v, w in pairwise(a):
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