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Principal component analysis in Python
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Months later, here's a small class PCA, and a picture:
#!/usr/bin/env python
""" a small class for Principal Component Analysis
Usage:
p = PCA( A, fraction=0.90 )
In:
A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 columns
fraction: use principal components that...
How to deep copy a list?
...ist.
deepcopy(x, memo=None, _nil=[])
Deep copy operation on arbitrary Python objects.
See the following snippet -
>>> a = [[1, 2, 3], [4, 5, 6]]
>>> b = list(a)
>>> a
[[1, 2, 3], [4, 5, 6]]
>>> b
[[1, 2, 3], [4, 5, 6]]
>>> a[0][1] = 10
>>&g...
How can I compare two lists in python and return matches
I want to take two lists and find the values that appear in both.
19 Answers
19
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How does collections.defaultdict work?
I've read the examples in python docs, but still can't figure out what this method means. Can somebody help? Here are two examples from the python docs
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Iterate a list with indexes in Python
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python enumerate function will be satisfied your requirements
result = list(enumerate([1,3,7,12]))
print result
output
[(0, 1), (1, 3), (2, 7),(3,12)]
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What is pip's equivalent of `npm install package --save-dev`?
...ject with an existing requirements.txt, installing all requirements (I use Python3.7 but you can remove the --three if you do not) is as simple as:
pipenv --three install
Activating the virtualenv to run commands is also easy
pipenv shell
Installing requirements will automatically update the P...
Can modules have properties the same way that objects can?
With python properties, I can make it such that
6 Answers
6
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LaTeX package for syntax highlighting of code in various languages
...require jumping through a dozen hoops, upgrading to MiKTeX 2.8, installing Python, installing other components and so on. Minted documentation is poor and it doesn't support breaking long lines. But eventually I got it to render Java/XML in Eclipse colours! jevon.org/wiki/Eclipse_Pygments_Style
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Python base64 data decode
I have the following piece of base64 encoded data, and I want to use python base64 module to extract information from it. It seems that module does not work. Can anyone tell me how?
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How to get a complete list of object's methods and attributes?
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That is why the new __dir__() method has been added in python 2.6
see:
http://docs.python.org/whatsnew/2.6.html#other-language-changes (scroll down a little bit)
http://bugs.python.org/issue1591665
sh...