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Is there a difference between “==” and “is”?
...s out the reference implementation of Python caches integer objects in the range -5..256 as singleton instances for performance reasons. Here's an example demonstrating this:
>>> for i in range(250, 260): a = i; print "%i: %s" % (i, a is int(str(i)));
...
250: True
251: True
252: True
253...
How to find out what type of a Mat object is with Mat::type() in OpenCV
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For debugging purposes in case you want to look up a raw Mat::type in a debugger:
+--------+----+----+----+----+------+------+------+------+
| | C1 | C2 | C3 | C4 | C(5) | C(6) | C(7) | C(8) |
+--------+----+----+----+----+------+------+------+------+
| CV_8U | 0 | ...
Sass combining parent using ampersand (&) with type selectors
...;.class { ... } } so why shouldn't you be able to do the same thing with a raw html element. Just because there was no way to do it as of the time OP posted doesn't mean he was incorrect to want the functionality to actually do it.
– Mike Mellor
Oct 3 '17 at 14...
Check if a given key already exists in a dictionary
...you wanted a default, you can always use dict.get():
d = dict()
for i in range(100):
key = i % 10
d[key] = d.get(key, 0) + 1
and if you wanted to always ensure a default value for any key you can either use dict.setdefault() repeatedly or defaultdict from the collections module, like so:...
C# using streams
....io.stream.aspx
Memorystream and FileStream are streams used to work with raw memory and Files respectively...
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Test if string is a number in Ruby on Rails
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From Rails 'validates_numericality_of': raw_value.to_s =~ /\A[+-]?\d+\Z/
– Morten
Aug 17 '12 at 20:09
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Android. WebView and loadData
..., I tried with UTF-8 and with latin-1 and with ISO-8859-1, but saw still strange signs instead of ü, ö, ä. But I have another idea, I'll try to convert byte stream from server into string using right encoding. maybe, that'll help me
– Tima
Dec 7 '10 at 10:14...
What is the difference between an expression and a statement in Python?
...lue", which can be any Python object. Examples:
3 + 5
map(lambda x: x*x, range(10))
[a.x for a in some_iterable]
yield 7
Statements (see 1, 2), on the other hand, are everything that can make up a line (or several lines) of Python code. Note that expressions are statements as well. Examples:
...
How do I get whole and fractional parts from double in JSP/Java?
...hole: 3
Fraction: .25
That's it. No need to massage it with help of raw Java code.
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What is the point of function pointers?
...jects) for the same result.
The functors have a number of advantages over raw function pointers, due to their object nature, notably:
They may present several overloads of the operator()
They can have state / reference to existing variables
They can be built on the spot (lambda and bind)
I pers...