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How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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Why is it slower to iterate over a small string than a small list?
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TL;DR
The actual speed difference is closer to 70% (or more) once a lot of the overhead is removed, for Python 2.
Object creation is not at fault. Neither method creates a new object, as one-character strings are cached.
The difference is unobvious, but is likely created f...
RegEx to parse or validate Base64 data
...sion to match Base64 encoded words, you can use the following:
^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$
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Multiple linear regression in Python
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102
sklearn.linear_model.LinearRegression will do it:
from sklearn import linear_model
clf = linea...
From inside of a Docker container, how do I connect to the localhost of the machine?
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I do not want to inherit the child opacity from the parent in CSS
...e 'a' is the level of transparency.
So instead of:
background-color: rgb(0,0,255); opacity: 0.5;
use
background-color: rgba(0,0,255,0.5);
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Applying a function to every row of a table using dplyr?
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202
As of dplyr 0.2 (I think) rowwise() is implemented, so the answer to this problem becomes:
iri...
Vagrant reverse port forwarding?
...ROR -o IdentitiesOnly=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you want with the -R guestport:host:hostport option. So, if you wanted to connect to port 12345 on the guest and have it forwarded to localhost:80, you would use this comm...
What are the main uses of yield(), and how does it differ from join() and interrupt()?
...nd Java 6.
In Java 5, Thread.yield() calls the Windows API call Sleep(0). This
has the special effect of clearing the current thread's quantum and
putting it to the end of the queue for its priority level. In other
words, all runnable threads of the same priority (and those of greater
p...
What is the >>>= operator in C?
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The line:
while( a[ 0xFULL?'\0':-1:>>>=a<:!!0X.1P1 ] )
contains the digraphs :> and <:, which translate to ] and [ respectively, so it's equivalent to:
while( a[ 0xFULL?'\0':-1 ] >>= a[ !!0X.1P1 ] )
The literal 0xFUL...