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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 = ...
When do I use fabs and when is it sufficient to use std::abs?
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In C++, it's always sufficient to use std::abs; it's overloaded for all the numerical types.
In C, abs only works on integers, and you need fabs for floating point values. These are available in C++ (along with all of the C library), but there's no need to use them.
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How do I base64 encode (decode) in C?
... *output_length = 4 * ((input_length + 2) / 3);
char *encoded_data = malloc(*output_length);
if (encoded_data == NULL) return NULL;
for (int i = 0, j = 0; i < input_length;) {
uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_b = ...
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...
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...