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When to use symbols instead of strings in Ruby?
...iers. For Ruby < 2.2 only use symbols when they aren't generated dynamically, to avoid memory leaks.
Full answer
The only reason not to use them for identifiers that are generated dynamically is because of memory concerns.
This question is very common because many programming languages don't h...
Multiple columns index when using the declarative ORM extension of sqlalchemy
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answered Jul 8 '11 at 16:00
zzzeekzzzeek
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Using OR in SQLAlchemy
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answered Oct 30 '11 at 0:22
Bastien LéonardBastien Léonard
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Input and output numpy arrays to h5py
I have a Python code whose output is a sized matrix, whose entries are all of the type float . If I save it with the extension .dat the file size is of the order of 500 MB. I read that using h5py reduces the file size considerably. So, let's say I have the 2D numpy array named A . How do I ...
Error installing mysql2: Failed to build gem native extension
I am having some problems when trying to install mysql2 gem for Rails. When I try to install it by running bundle install or gem install mysql2 it gives me the following error:
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Can I call memcpy() and memmove() with “number of bytes” set to zero?
... the length of the array for a
function, n can have the value zero on a call to that function. Unless explicitly stated
otherwise in the description of a particular function in this subclause, pointer arguments
on such a call shall still have valid values, as described in 7.1.4. On such a call...
How do I check if there are duplicates in a flat list?
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Use set() to remove duplicates if all values are hashable:
>>> your_list = ['one', 'two', 'one']
>>> len(your_list) != len(set(your_list))
True
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How to forward declare a template class in namespace std?
...rs. Of course, I know that there are more template params for std::list (allocator I think). But, that is beside the point. Do I have to know the full template declaration of a template class to be able to forward declare it?
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sqlalchemy unique across multiple columns
...: which RDBMS do you use?
– van
Oct 11 '13 at 9:30
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Thanks, but my question was: did you use SA ...
top -c command in linux to filter processes listed based on processname
Top lists all the processes, there are good options to filter the processes by username by using the option -u but I am wondering if there is any easy way to filter the processes based on processname listed under COMMAND column of the top output.
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