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Any reason not to use '+' to concatenate two strings?
... because the Python interpreter has to create a new string object for each iteration, and it ends up taking quadratic time. (Recent versions of CPython can apparently optimize this in some cases, but other implementations can't, so programmers are discouraged from relying on this.) ''.join is the ...
What is a method that can be used to increment letters?
...arCodeAt(0) + 1);
}
nextChar('a');
As others have noted, the drawback is it may not handle cases like the letter 'z' as expected. But it depends on what you want out of it. The solution above will return '{' for the character after 'z', and this is the character after 'z' in ASCII, so it could be ...
How do I parse an ISO 8601-formatted date?
...uestion, but also other ISO 8601 date and time strings that don't comply with RFC 3339 (such as ones with no UTC offset, or ones that represent only a date).
>>> import dateutil.parser
>>> dateutil.parser.isoparse('2008-09-03T20:56:35.450686Z') # RFC 3339 format
datetime.datetime...
Multiple linear regression in Python
...
sklearn.linear_model.LinearRegression will do it:
from sklearn import linear_model
clf = linear_model.LinearRegression()
clf.fit([[getattr(t, 'x%d' % i) for i in range(1, 8)] for t in texts],
[t.y for t in texts])
Then clf.coef_ will have the regression coeffi...
Extracting bits with a single multiplication
...ue used in an answer to another question , and would like to understand it a little better.
5 Answers
...
Installing python module within code
I need to install a package from PyPi straight within my script.
Maybe there's some module or distutils ( distribute , pip etc.) feature which allows me to just execute something like pypi.install('requests') and requests will be installed into my virtualenv.
...
How is a CRC32 checksum calculated?
Maybe I'm just not seeing it, but CRC32 seems either needlessly complicated, or insufficiently explained anywhere I could find on the web.
...
How to move a model between two Django apps (Django 1.7)
...'t really focus too much on the structure, however now I am further along with Django it has started to appear that my project layout mainly my models are horrible in structure.
...
Removing duplicates from a list of lists
...gt;> k = [[1, 2], [4], [5, 6, 2], [1, 2], [3], [4]]
>>> import itertools
>>> k.sort()
>>> list(k for k,_ in itertools.groupby(k))
[[1, 2], [3], [4], [5, 6, 2]]
itertools often offers the fastest and most powerful solutions to this kind of problems, and is well worth g...
The most accurate way to check JS object's type?
...lass of an object:
Object.prototype.toString.call(t);
http://bonsaiden.github.com/JavaScript-Garden/#types
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