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Selecting/excluding sets of columns in pandas [duplicate]
I would like to create views or dataframes from an existing dataframe based on column selections.
9 Answers
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Most efficient way to concatenate strings in JavaScript?
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Seems based on benchmarks at JSPerf that using += is the fastest method, though not necessarily in every browser.
For building strings in the DOM, it seems to be better to concatenate the string first and then add to the DOM, rath...
How to find a table having a specific column in postgresql
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I've used the query of @Roman Pekar as a base and added schema name (relevant in my case)
select n.nspname as schema ,c.relname
from pg_class as c
inner join pg_attribute as a on a.attrelid = c.oid
inner join pg_namespace as n on c.relnamespace = n.oid
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Python + Django page redirect
...o 1.5. Use 'RedirectView' instead: docs.djangoproject.com/en/1.5/ref/class-based-views/base/…
– Yonatan
Apr 29 '13 at 23:42
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How can I shuffle the lines of a text file on the Unix command line or in a shell script?
... to head.
A performance comparison is made.
POSIX-compliant function based on awk, sort, and cut, adapted from the OP's own answer:
shuf() { awk 'BEGIN {srand(); OFMT="%.17f"} {print rand(), $0}' "$@" |
sort -k1,1n | cut -d ' ' -f2-; }
Perl-based function - adapted from Moo...
What is the __DynamicallyInvokable attribute for?
... comment on the OP's Q - one case where the CLR seems to be doing trickery based on this is in the handling 'slight' moves of methods (e.g. down one level onto a new base class) under unification
– Ruben Bartelink
Feb 13 '13 at 13:29
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What effect(s) can the virtual keyword have in Entity Framework 4.1 POCO Code First?
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properties that are persisted.
Finally, you must declare collection
based relationship navigation
properties as ICollection<T> only.
They cannot be a concrete
implementation or another interface
that derives from ICollection<T> (a
difference from the Deferred Loading
p...
Start an Activity with a parameter
...e do not control the Intent which launches the Activity.
You can create a base-class Activity that has a constructor with a parameter, then a derived class that has a default constructor which calls the base-class constructor with a value, as so:
class BaseActivity extends Activity
{
public Ba...
How to join absolute and relative urls?
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es = ['http://127.0.0.1', 'test1', 'test4', 'test6.xml']
base = ''
map(lambda e: urlparse.urljoin(base, e), es)
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How to “perfectly” override a dict?
... write an object that behaves like a dict quite easily with ABCs (Abstract Base Classes) from the collections.abc module. It even tells you if you missed a method, so below is the minimal version that shuts the ABC up.
from collections.abc import MutableMapping
class TransformedDict(MutableMappi...