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Add column with constant value to pandas dataframe [duplicate]
...ods to gain some intuition for alignment works with objects that have partially, totally, and not-aligned-all aligned indices. For example here's how DataFrame.align() works with partially aligned indices:
In [7]: from pandas import DataFrame
In [8]: from numpy.random import randint
In [9]: df = ...
What's the best way of structuring data on firebase?
... opposed to RDBMS, is that it's tempting to nest data because we can. Generally, you want to normalize data to some extent (just as you would do with SQL) despite the lack of join statements and queries.
You also want to denormalize in places where read efficiency is a concern. This is a technique...
Regular Expression for alphanumeric and underscores
...o or more of the given characters
$ : end of string
If you don't want to allow empty strings, use + instead of *.
As others have pointed out, some regex languages have a shorthand form for [a-zA-Z0-9_]. In the .NET regex language, you can turn on ECMAScript behavior and use \w as a shorthand (y...
JPA: unidirectional many-to-one and cascading delete
...e as ON DELETE CASCADE. You'll need to invoke EntityManager.clear() after calling EntityManager.remove(parent) as the persistence context needs to be refreshed - the child entities are not supposed to exist in the persistence context after they've been deleted in the database.
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How to get the sizes of the tables of a MySQL database?
I can run this query to get the sizes of all tables in a MySQL database:
16 Answers
16...
What do the different readystates in XMLHttpRequest mean, and how can I use them?
...em except for 4.
Some XMLHttpRequest implementations may let you see partially received responses in responseText when readyState==3, but this isn't universally supported and shouldn't be relied upon.
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API vs. Webservice [closed]
...s don't necessarily use HTTP, but this is almost always the case and is usually assumed unless mentioned otherwise.
For examples of web services specifically, see SOAP, REST, and XML-RPC. For an example of another type of API, one written in C for use on a local machine, see the Linux Kernel API.
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Android error: Failed to install *.apk on device *: timeout
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Ran in to this problem usually with my Galaxy Tab. Increasing the timeout to 10s seems to have fixed it for now. Thanks!
– Jon Turner
Mar 30 '11 at 22:56
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Authorative way to override onMeasure()?
...velopment uses MeasureSpec to calculate the dimensions, then ends with a call to setMeasuredDimension(). For example:
8 An...
Why am I seeing an “origin is not allowed by Access-Control-Allow-Origin” error here? [duplicate]
...to use javascript. You make a request and results are encapsulated into a callback function which is run in the client. It's the same as linking a new script tag into the head part of your html (you know that you can load scripts from different domains than yours here).
However, to use jsonp the ser...