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Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers
...6. , 2.2]])
# Creating pandas dataframe from numpy array
>>> dataset = pd.DataFrame({'Column1': data[:, 0], 'Column2': data[:, 1]})
>>> print(dataset)
Column1 Column2
0 5.8 2.8
1 6.0 2.2
...
Automatically capture output of last command into a variable using Bash?
...AND='LAST="`cat /tmp/x`"; exec >/dev/tty; exec > >(tee /tmp/x)'
Set this bash environmental variable and issues commands as desired. $LAST will usually have the output you are looking for:
startide seth> fortune
Courtship to marriage, as a very witty prologue to a very dull play.
...
Determine if Python is running inside virtualenv
..._prefix.
Using the VIRTUAL_ENV environment variable is not reliable. It is set by the virtualenv activate shell script, but a virtualenv can be used without activation by directly running an executable from the virtualenv's bin/ (or Scripts) directory, in which case $VIRTUAL_ENV will not be set. Or ...
Python Pandas: Get index of rows which column matches certain value
...
Simple way is to reset the index of the DataFrame prior to filtering:
df_reset = df.reset_index()
df_reset[df_reset['BoolCol']].index.tolist()
Bit hacky, but it's quick!
...
Standard deviation of a list
...ta list.
Sample std: You need to pass ddof (i.e. Delta Degrees of Freedom) set to 1, as in the following example:
numpy.std(< your-list >, ddof=1)
The divisor used in calculations is N - ddof, where N represents the number of elements. By default ddof is zero.
It calculates sampl...
C++ Returning reference to local variable
...- and then suddenly cease to function after one particularly deeply nested set of functions, or a function with really huge sized or many local objects, reaches that stack-memory again.
It even can happen that you reach the same program part again, and overwrite your old local function variable wit...
How do I install an R package from source?
...
If you have the file locally, then use install.packages() and set the repos=NULL:
install.packages(path_to_file, repos = NULL, type="source")
Where path_to_file would represent the full path and file name:
On Windows it will look something like this: "C:\\RJSONIO_0.2-3.tar.gz".
O...
How to join (merge) data frames (inner, outer, left, right)
...you, you should also look into the data.table package - that's a whole new set of join syntax, but it's radically faster than anything we're talking about here.
– Matt Parker
Feb 12 '13 at 16:22
...
Many-to-many relationship with the same model in rails?
...connection.save!
=> true
Instead of creating the association and then setting the category separately, you can also just create a PostConnection and be done with it:
>> b.posts = []
=> []
>> PostConnection.create(
?> :post_a => b, :post_b => a,
?> :category =>...
Is it possible to use argsort in descending order?
..._n).flags['OWNDATA']
True
So if you time each, with this very small data set:
>>> import timeit
>>> timeit.timeit('(-avgDists).argsort()[:3]', setup="from __main__ import avgDists")
4.2879798610229045
>>> timeit.timeit('avgDists.argsort()[::-1][:3]', setup="from __main_...