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How to sort two lists (which reference each other) in the exact same way
... of 10000 random ints): %timeit index = range(len(l1)); index.sort(key=l1.__getitem__); map(l1.__getitem__, index); map(l2.__getitem__, index) 100 loops, best of 3: 8.04 ms per loop (vs 9.17 ms, 9.07 ms for senderle's timits)
– Quantum7
Aug 12 '13 at 21:35
...
Does MongoDB's $in clause guarantee order
...ly have two options.
So let's say that you were matching on the values of _id in your documents with an array that is going to be passed in to the $in as [ 4, 2, 8 ].
Approach using Aggregate
var list = [ 4, 2, 8 ];
db.collection.aggregate([
// Match the selected documents by "_id"
...
How to pretty print nested dictionaries?
...ues in Py2, it's cause it can't handle Unicode properly without hacks like __future__ that the answer now mentions, so you have to employ those wherever needed (or update to 3 already).
– sudo
Feb 14 '18 at 18:10
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Meaning of @classmethod and @staticmethod for beginner? [duplicate]
...thod can have no parameters at all.
Example
class Date(object):
def __init__(self, day=0, month=0, year=0):
self.day = day
self.month = month
self.year = year
@classmethod
def from_string(cls, date_as_string):
day, month, year = map(int, date_as_string...
Flask-SQLAlchemy import/context issue
...
The flask_sqlalchemy module does not have to be initialized with the app right away - you can do this instead:
# apps.members.models
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class Member(db.Model):
# fields her...
Sharing a result queue among several processes
... can I share a queue with asynchronous worker processes started with apply_async ? I don't need dynamic joining or anything else, just a way for the workers to (repeatedly) report their results back to base.
...
Replace all non Alpha Numeric characters, New Lines, and multiple White Space with one Space
... \W leaves the underscore. A short equivalent for [^a-zA-Z0-9] would be [\W_]
text.replace(/[\W_]+/g," ");
\W is the negation of shorthand \w for [A-Za-z0-9_] word characters (including the underscore)
Example at regex101.com
...
How to convert vector to array
...?
If you're calling an API function that expects the former, you can do do_something(&v[0], v.size()), where v is a vector of doubles. The elements of a vector are contiguous.
Otherwise, you just have to copy each element:
double arr[100];
std::copy(v.begin(), v.end(), arr);
Ensure not only...
Dealing with commas in a CSV file
....Read ) )
{
}
public CsvReader( Stream stream )
{
__reader = new StreamReader( stream );
}
public System.Collections.IEnumerable RowEnumerator
{
get {
if ( null == __reader )
throw new System.ApplicationException( "I can't sta...
How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...