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What is the difference between NaN and None?
...= pd.Series([1, None], dtype=object)
s_good = pd.Series([1, np.nan])
In [13]: s_bad.dtype
Out[13]: dtype('O')
In [14]: s_good.dtype
Out[14]: dtype('float64')
Jeff comments (below) on this:
np.nan allows for vectorized operations; its a float value, while None, by definition, forces object ty...
Command-line Unix ASCII-based charting / plotting tool
...
136
Try gnuplot. It has very powerful graphing possibilities.
It can output to your terminal in th...
How to display unique records from a has_many through relationship?
...ay to display unique records from a has_many, through relationship in Rails3.
4 Answers
...
Hide/Show Column in an HTML Table
...ce improvement.
– Brian Fisher
Jan 23 '09 at 7:04
2
This approach worked wonders for me, performa...
git update-index --assume-unchanged on directory
... |
edited May 15 '19 at 13:07
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answered Sep 5 '12 at 20:03
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How can I change property names when serializing with Json.net?
...
3 Answers
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How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
... INTO `usage`
(`thing_id`, `times_used`, `first_time_used`)
VALUES
(4815162342, 1, NOW())
ON DUPLICATE KEY UPDATE
`times_used` = `times_used` + 1
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How to determine if a number is a prime with regex?
...he number supplied. So the string has three characters if and only if n == 3.
.?
The first part of the regex says, "any character, zero or one times". So basically, is there zero or one character-- or, per what I mentioned above, n == 0 || n == 1. If we have the match, then return the negation of...
Dump a NumPy array into a csv file
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913
numpy.savetxt saves an array to a text file.
import numpy
a = numpy.asarray([ [1,2,3], [4,5,6],...