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Efficient evaluation of a function at every cell of a NumPy array
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You could just vectorize the function and then apply it directly to a Numpy array each time you need it:
import numpy as np
def f(x):
return x * x + 3 * x - 2 if x > 0 else x * 5 + 8
f = np.vectorize(f) # or use a different name if you want to keep the...
What is the difference between “ is None ” and “ ==None ”
...o quote:
A class is free to implement
comparison any way it chooses, and it
can choose to make comparison against
None mean something (which actually
makes sense; if someone told you to
implement the None object from
scratch, how else would you get it to
compare True against itself...
Access an arbitrary element in a dictionary in Python
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On Python 3, non-destructively and iteratively:
next(iter(mydict.values()))
On Python 2, non-destructively and iteratively:
mydict.itervalues().next()
If you want it to work in both Python 2 and 3, you can use the six package:
six.next(six.itervalue...
CMake: Project structure with unit tests
...tructure my project to include the production sources (in src subfolder) and tests (in test subfolder). I am using CMake to build this. As a minimal example I have the following files:
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Why should Java ThreadLocal variables be static
... avoid any static fields in your class - make the class itself a singleton and then you can safely use the an instance level ThreadLocal as long as you have that singleton available globally.
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How do I resolve a HTTP 414 “Request URI too long” error?
...ried using POST at first, but this is an update operation on the database, and I am refreshing the orginal page using the values that were originally posted to that page.
– JPro
May 23 '10 at 12:42
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git command to move a folder inside another
I have created a folder common with a bunch of source files and folders.
9 Answers
9...
Given a URL to a text file, what is the simplest way to read the contents of the text file?
...xt file, what is the simplest way to access the contents off the text file and print the contents of the file out locally line-by-line without saving a local copy of the text file?
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Detecting when the 'back' button is pressed on a navbar
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- (BOOL)isMovingFromParentViewController makes sense when you are pushing and popping controllers in a navigation stack.
However, if you are presenting modal view controllers you should use - (BOOL)isBeingDismissed instead:
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:ani...
Pandas selecting by label sometimes return Series, sometimes returns DataFrame
In Pandas, when I select a label that only has one entry in the index I get back a Series, but when I select an entry that has more then one entry I get back a data frame.
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