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Why does the lock object have to be static?
It is very common to use a private static readonly object for locking in multi threading.
I understand that private reduces the entry points to the locking object by tightening the encapsulation and therefore access to the most essential.
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Unix shell script find out which directory the script file resides?
Basically I need to run the script with paths related to the shell script file location, how can I change the current directory to the same directory as where the script file resides?
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How to force a html5 form validation without submitting it via jQuery
I have this form in my app and I will submit it via AJAX, but I want to use HTML5 for client-side validation. So I want to be able to force the form validation, perhaps via jQuery.
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How to write DataFrame to postgres table?
There is DataFrame.to_sql method, but it works only for mysql, sqlite and oracle databases. I cant pass to this method postgres connection or sqlalchemy engine.
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Foreign key constraints: When to use ON UPDATE and ON DELETE
...sing MySQL Workbench, which is pretty cool because you can do diagrams and it converts them :P
3 Answers
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Intellij IDEA show javadoc automatically
When I am coding at Netbeans it autocompletes the code and show Javadocs. However when I am using Intellij IDEA if I click Ctrl+Space I can see the auto-complete and if I click Ctrl+Q I can see the javadoc seperately.
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Using GPU from a docker container?
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Regan's answer is great, but it's a bit out of date, since the correct way to do this is avoid the lxc execution context as Docker has dropped LXC as the default execution context as of docker 0.9.
Instead it's better to tell docker about the nvidia de...
How do I display a text file content in CMD?
I want to display the content of a text file in a CMD window. In addition, I want to see the new lines that added to file, like tail -f command in Unix.
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How to avoid circular imports in Python? [duplicate]
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Doesn't seem to work with submodules import foobar.mod_a and import foobar.mod_b doesn't work like described above.
– Nick
Oct 2 '13 at 0:39
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How to toggle a value in Python
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Solution using XOR
If the value toggles between 0 and 1, you can use a bitwise exclusive-or:
>>> x = 1
>>> x ^= 1
>>> x
0
>>> x ^= 1
>>> x
1
The technique generalizes to any pair of integers. The xor-by-one step is replaced with a xor-by-precompute...