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What does “hashable” mean in Python?
...ue which never changes during its lifetime (it needs a __hash__() method), and can be compared to other objects (it needs an __eq__() or __cmp__() method). Hashable objects which compare equal must have the same hash value.
Hashability makes an object usable as a dictionary key and a set member...
How to create GUID / UUID?
...vaScript. I'm not sure what routines are available on all browsers, how "random" and seeded the built-in random number generator is, etc.
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C: What is the difference between ++i and i++?
In C, what is the difference between using ++i and i++ , and which should be used in the incrementation block of a for loop?
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How do I clone a Django model instance object and save it to the database?
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Just change the primary key of your object and run save().
obj = Foo.objects.get(pk=<some_existing_pk>)
obj.pk = None
obj.save()
If you want auto-generated key, set the new key to None.
More on UPDATE/INSERT here.
Official docs on copying model instances: h...
Find a value anywhere in a database
Given a #, how do I discover in what table and column it could be found within?
18 Answers
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iPhone Safari Web App opens links in new window
...is launched from Home Screen, all links will open in new window in Safari (and lose full screen functionality). How can I prevent it? I couldn't find any help, only the same unanswered question.
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How do I choose grid and block dimensions for CUDA kernels?
This is a question about how to determine the CUDA grid, block and thread sizes. This is an additional question to the one posted here .
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Matplotlib 2 Subplots, 1 Colorbar
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Just place the colorbar in its own axis and use subplots_adjust to make room for it.
As a quick example:
import numpy as np
import matplotlib.pyplot as plt
fig, axes = plt.subplots(nrows=2, ncols=2)
for ax in axes.flat:
im = ax.imshow(np.random.random((10,10...
Benefits of using the conditional ?: (ternary) operator
What are the benefits and drawbacks of the ?: operator as opposed to the standard if-else statement. The obvious ones being:
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Why should I use Google's CDN for jQuery?
...This makes the time-to-download very small, because it is super compressed and it isn't compressed on the fly.)
It reduces the amount of bandwidth used by your server. (Google is basically offering free bandwidth.)
It ensures that the user will get a geographically close response. (Google has serv...