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Reset C int array to zero : the fastest way?
...all-bits-zero is a valid representation of 0 for all integer types in all existing C and C++ implementations, which is why the committee was able to add that requirement. (There is no similar guarantee for floating-point or pointer types.)
– Keith Thompson
Jun ...
Drawing a dot on HTML5 canvas [duplicate]
...rawing a line on the HTML5 canvas is quite straightforward using the context.moveTo() and context.lineTo() functions.
6...
Are tuples more efficient than lists in Python?
...tuple is much faster than assigning a list.
>>> def a():
... x=[1,2,3,4,5]
... y=x[2]
...
>>> def b():
... x=(1,2,3,4,5)
... y=x[2]
...
>>> import dis
>>> dis.dis(a)
2 0 LOAD_CONST 1 (1)
3 LOAD_CONST ...
Using LINQ to remove elements from a List
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Well, it would be easier to exclude them in the first place:
authorsList = authorsList.Where(x => x.FirstName != "Bob").ToList();
However, that would just change the value of authorsList instead of removing the authors from the previous collection....
Print a string as hex bytes?
...
Your can transform your string to a int generator, apply hex formatting for each element and intercalate with separator:
>>> s = "Hello world !!"
>>> ":".join("{:02x}".format(ord(c)) for c in s)
'48:65:6c:6c:6f:20:77:6f:72:6c:64:20:21:21
...
Create an empty list in python with certain size
...None, None, None, None, None, None, None, None]
Assigning a value to an existing element of the above list:
>>> l[1] = 5
>>> l
[None, 5, None, None, None, None, None, None, None, None]
Keep in mind that something like l[15] = 5 would still fail, as our list has only 10 element...
What is the benefit of using $() instead of backticks in shell scripts?
...ng to figure out if some form of escaping will work on the backticks.
An example, though somewhat contrived:
deps=$(find /dir -name $(ls -1tr 201112[0-9][0-9]*.txt | tail -1l) -print)
which will give you a list of all files in the /dir directory tree which have the same name as the earliest date...
Xml Namespace breaking my xpath! [duplicate]
I have the following XML:
5 Answers
5
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Converting string to numeric [duplicate]
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I suspect you are having a problem with factors. For example,
> x = factor(4:8)
> x
[1] 4 5 6 7 8
Levels: 4 5 6 7 8
> as.numeric(x)
[1] 1 2 3 4 5
> as.numeric(as.character(x))
[1] 4 5 6 7 8
Some comments:
You mention that your vector contains the characters "Do...
Complex numbers usage in python [closed]
...tting deeper into Python data types. I can't understand how to use a complex number. Please give me examples of usage of complex numbers in Python.
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