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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 = [(...
Enums and Constants. Which to use when?
...t to any other integral type except char like:
enum LongEnum : long {
foo,
bar,
}
You can cast explicitly from and implicitly to the the base type, which is useful in switch-statements. Beware that one can cast any value of the base type to an enum, even if the enum has no member with the...
How can I create directories recursively? [duplicate]
...
Specifically: os.makedirs(os.path.join("/home/dail", "first", "second", "third"))
– mseery
May 14 '11 at 22:41
...
Reset auto increment counter in postgres
...ated the table product with an id column, then the sequence is not simply called product, but rather product_id_seq (that is, ${table}_${column}_seq).
This is the ALTER SEQUENCE command you need:
ALTER SEQUENCE product_id_seq RESTART WITH 1453
You can see the sequences in your database using the...
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,...
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...
How do you iterate through every file/directory recursively in standard C++?
...e to the standard.
An example, taken straight from the website:
bool find_file( const path & dir_path, // in this directory,
const std::string & file_name, // search for this name,
path & path_found ) // placing path here if found
{
...
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...
force Maven to copy dependencies into target/lib
...tions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${proj...
REST vs JSON-RPC? [closed]
...ions(HTTP headers + representation). For example:
It's possible (and actually mandatory) to embed links annotated with link relation types which convey meanings of these URIs;
Client implementations do not need to depend on particular procedure names and arguments. Instead, clients depend on messa...