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How to drop rows of Pandas DataFrame whose value in a certain column is NaN
...ta, including dropna(), is built into pandas explicitly. Aside from potentially improved performance over doing it manually, these functions also come with a variety of options which may be useful.
In [24]: df = pd.DataFrame(np.random.randn(10,3))
In [25]: df.iloc[::2,0] = np.nan; df.iloc[::4,1] ...
Reset all changes after last commit in git
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@RobertSiemer Actually, it can! If you have any folders composed entirely of ignored files it will remove those folders thus deleting ignored files. Consider a .gitignore file like the one here: stackoverflow.com/q/25554504/456645. In this e...
How to detect page zoom level in all modern browsers?
...n bigger mess than it was when this question was first asked. From reading all the responses and blog posts I could find, here's a summary. I also set up this page to test all these methods of measuring the zoom level.
Edit (2011-12-12): I've added a project that can be cloned: https://github.com/t...
What is Double Brace initialization in Java?
...as an implicit this pointer to the surrounding outer class. Whilst not normally a problem, it can cause grief in some circumstances e.g. when serialising or garbage collecting, and it's worth being aware of this.
share
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How to list running screen sessions?
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To list all of the screen sessions for a user, run the following command as that user:
screen -ls
To see all screen sessions on a specific machine you can do:
ls -laR /var/run/screen/
I get this on my machine:
gentle ~ # ls -l...
Change / Add syntax highlighting for a language in Sublime 2/3
...ince Sublime Text 3 is using the .sublime-package zip file format to store all the default settings it's not very straightforward to edit the individual files.
Unfortunately, not all themes contain all scopes, so you'll need to play around with different ones to find one that looks good, and gives ...
Git submodule push
... June 2012) mentions:
"git push --recurse-submodules" learned to optionally look into the histories of submodules bound to the superproject and push them out.
Probably done after this patch and the --on-demand option:
recurse-submodules=<check|on-demand>::
Make sure all submodule c...
Mutable vs immutable objects
... were based upon mutable values. Those values changed outside the map and all of the hashing became obsolete. Theorists like to harp on this point, but in practice I haven't found it to be too much of an issue.
Another aspect is the logical "reasonability" of your code. This is a hard term to def...
Howto: Clean a mysql InnoDB storage engine?
...lib/mysql/ibdata1 is the busiest file in the InnoDB infrastructure. It normally houses six types of information:
Table Data
Table Indexes
MVCC (Multiversioning Concurrency Control) Data
Rollback Segments
Undo Space
Table Metadata (Data Dictionary)
Double Write Buffer (background writing to prev...
~x + ~y == ~(x + y) is always false?
...=> -1 == -2
Hence, a contradiction. Therefore, ~(x+y) != ~x + ~y for all x and y (mod 2n).
*It is interesting to note that on a machine with one's complement arithmetic, the equality actually holds true for all x and y. This is because under one's complement, ~x = -x. Thus, ~x + ~y == -x + ...