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Python group by
...
Python's built-in itertools module actually has a groupby function , but for that the elements to be grouped must first be sorted such that the elements to be grouped are contiguous in the list:
from operator import itemgetter
sortkeyfn = itemgetter(1)
input = [(...
Cannot overwrite model once compiled Mongoose
...y have a schema defined, and then you are defining the schema again. Generally what you should do is instantiate the schema once, and then have a global object call it when it needs it.
For example:
user_model.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var userSchema...
What is a JavaBean exactly?
...
A JavaBean is just a standard
All properties private (use getters/setters)
A public no-argument constructor
Implements Serializable.
That's it. It's just a convention. Lots of libraries depend on it though.
With respect to Serializable, from the API d...
Restore the state of std::cout after manipulating it
...lude <iostream> or #include <ios> then when required:
std::ios_base::fmtflags f( cout.flags() );
//Your code here...
cout.flags( f );
You can put these at the beginning and end of your function, or check out this answer on how to use this with RAII.
...
How to write a multidimensional array to a text file?
...is specified by the comments kwarg). (This looks more verbose than it actually is...)
import numpy as np
# Generate some test data
data = np.arange(200).reshape((4,5,10))
# Write the array to disk
with open('test.txt', 'w') as outfile:
# I'm writing a header here just for the sake of readabil...
force Maven to copy dependencies into target/lib
...tions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${proj...
_csv.Error: field larger than field limit (131072)
...
The csv file might contain very huge fields, therefore increase the field_size_limit:
import sys
import csv
csv.field_size_limit(sys.maxsize)
sys.maxsize works for Python 2.x and 3.x. sys.maxint would only work with Python 2.x (SO: what-is-sys-maxint-in-python-3)
Update
As Geoff pointed out,...
How to get a random number in Ruby
...6). A roll in craps could be simulated with 2 + rand(6) + rand(6).
Finally, if you just need a random float, just call rand with no arguments.
As Marc-André Lafortune mentions in his answer below (go upvote it), Ruby 1.9.2 has its own Random class (that Marc-André himself helped to debug,...
Maven2: Missing artifact but jars are in place
... settings in the global or user settings.
Check you're using the Maven installation you expect. By default m2eclipse uses the embedder, if you have a separate installation you may want to configure m2eclipse to use the external installation so that CLI and Eclipse builds are consistent. This also en...
Replace only some groups with Regex
...attern = @"-(\d+)-";
var replaced = Regex.Replace(text, pattern, (_match) =>
{
Group group = _match.Groups[1];
string replace = "AA";
return String.Format("{0}{1}{2}", _match.Value.Substring(0, group.Index - _match.Index), replace, _match.Value...