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Django database query: How to get object by id?
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If you want to get an object, using get() is more straightforward:
obj = Class.objects.get(pk=this_object_id)
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sqlalchemy IS NOT NULL select
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The other answer is the preferred answer now; it also avoids many IDEs including PyCharm from generating warnings.
– Antti Haapala
Oct 6 '16 at 7:21
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Objective-C declared @property attributes (nonatomic, copy, strong, weak)
...tching of data)
Copy
copy is required when the object is mutable. Use this if you need the value of the object as it is at this moment, and you don't want that value to reflect any changes made by other owners of the object. You will need to release the object when you are finished with it because y...
How do I install from a local cache with pip?
... downloaded and added to the PIP_DOWNLOAD_CACHE directory. For instance, I now have quite a few Django packages.
This doesn't remove the need for network access, as stated in the pip news, so it's not the answer for creating new virtualenvs on the airplane, but it's still great.
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Adding a new value to an existing ENUM Type
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NOTE if you're using PostgreSQL 9.1 or later, and you are ok with making changes outside of a transaction, see this answer for a simpler approach.
I had the same problem few days ago and found this post. So my answer can be hel...
Android Writing Logs to text File
... and Android logging
Log4j is generic java logging implementation and is now a project of
Apache software foundation. It is not Android specific and so has
some incompatibilities with Android.
SL4J is not a logging implementation, It is an abstraction layer. It
helps avoid a situations like, each...
Matplotlib: “Unknown projection '3d'” error
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First off, I think mplot3D worked a bit differently in matplotlib version 0.99 than it does in the current version of matplotlib.
Which version are you using? (Try running: python -c 'import matplotlib; print matplotlib."__version__")
I'm guessing you're running v...
Subprocess changing directory
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To run your_command as a subprocess in a different directory, pass cwd parameter, as suggested in @wim's answer:
import subprocess
subprocess.check_call(['your_command', 'arg 1', 'arg 2'], cwd=working_dir)
A child process can't change its parent's working directo...
Changing password with Oracle SQL Developer
...pdating the password using SQL Developer is:
alter user user_name identified by new_password replace
old_password ;
You can check more options for this command here: ALTER USER-Oracle DOCS
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How do I calculate square root in Python?
...tance, x(0) in the second.
So it's not wrong, it's the right answer to a different question.
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