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Convert pandas dataframe to NumPy array
...taframe (df) to a numpy ndarray, use this code:
df.values
array([[nan, 0.2, nan],
[nan, nan, 0.5],
[nan, 0.2, 0.5],
[0.1, 0.2, nan],
[0.1, 0.2, 0.5],
[0.1, nan, 0.5],
[0.1, nan, nan]])
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What is the difference between a 'closure' and a 'lambda'?
...eturn func()
Because here, func is defined in anotherfunc, and in python 2.3 and greater (or some number like this) when they almost got closures correct (mutation still doesn't work), this means that it closes over anotherfunc's environment and can access variables inside of it. In Python 3.1+, ...
CPU Privilege Rings: Why rings 1 and 2 aren't used?
...of the modern protection model) only has a concept of privileged (ring 0,1,2) and unprivileged, the benefit to rings 1 and 2 were diminished greatly.
The intent by Intel in having rings 1 and 2 is for the OS to put device drivers at that level, so they are privileged, but somewhat separated from th...
Gmail Error :The SMTP server requires a secure connection or the client was not authenticated. The s
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25 Answers
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Validate phone number with JavaScript
...ectly. It validates that the phone number is in one of these formats:
(123) 456-7890 or 123-456-7890
26 Answers
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Else clause on Python while statement
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Checking images for similarity with OpenCV
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211
This is a huge topic, with answers from 3 lines of code to entire research magazines.
I will o...
Ruby: What is the easiest way to remove the first element from an array?
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291
"pop"ing the first element of an Array is called "shift" ("unshift"
being the operation of add...
Should I declare Jackson's ObjectMapper as a static field?
... would do that from the static block and it would be fine as well.
EDIT: (2013/10)
With 2.0 and above, above can be augmented by noting that there is an even better way: use ObjectWriter and ObjectReader objects, which can be constructed by ObjectMapper.
They are fully immutable, thread-safe, mean...