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PG undefinedtable error relation users does not exist
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At first, you shall detach all connections out of database. By default you use the development environment. Then try to reset database with the following:
rake db:reset
The rake db:reset task will drop the database and set it up again....
Does use of final keyword in Java improve the performance?
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Usually not. For virtual methods, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it lo...
Can I specify multiple users for myself in .gitconfig?
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You can manually edit those config files with git config --edit and git config --global --edit. And in case you missed Abizern’s comment, a repository’s config file is at <repo-root>/.git/config.
– Rory O'...
Unit testing that events are raised in C# (in order)
...ited May 12 '11 at 15:38
David Hall
30.2k1010 gold badges8484 silver badges119119 bronze badges
answered Oct 30 '08 at 1:45
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Leaflet - How to find existing markers, and delete markers?
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Should be a way to collect all of the layers used by Leaflet. :/
– jackyalcine
Aug 1 '12 at 21:39
10
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decorators in the python standard lib (@deprecated specifically)
...r('always', DeprecationWarning) # turn off filter
warnings.warn("Call to deprecated function {}.".format(func.__name__),
category=DeprecationWarning,
stacklevel=2)
warnings.simplefilter('default', DeprecationWarning) # reset filter
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How to check BLAS/LAPACK linkage in NumPy and SciPy?
... Given its widespread usefulness, numpy.__config__ should really be a public API. Nonetheless, you win this round, davost.
– Cecil Curry
Feb 5 '16 at 5:51
2
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How to JSON serialize sets?
...s.
As shown in the json module docs, this conversion can be done automatically by a JSONEncoder and JSONDecoder, but then you would be giving up some other structure you might need (if you convert sets to a list, then you lose the ability to recover regular lists; if you convert sets to a dictionar...
Difference between shared objects (.so), static libraries (.a), and DLL's (.so)?
... and shared objects are just different terms for the same thing - Windows calls them DLLs, while on UNIX systems they're shared objects, with the general term - dynamically linked library - covering both (even the function to open a .so on UNIX is called dlopen() after 'dynamic library').
They are ...
How do I catch a numpy warning like it's an exception (not just for testing)?
...ng: divide by zero encountered in divide
array([0])
>>> np.seterr(all='print')
{'over': 'warn', 'divide': 'warn', 'invalid': 'warn', 'under': 'ignore'}
>>> np.array([1])/0 #'print' mode
Warning: divide by zero encountered in divide
array([0])
This means that the warning you see...