View gist:8d69954e619a5961a37369275d6239c0
class Glob(object):
def change(glob):
glob.a = 2
print glob.a
View gist:5b5a08faaeced731d98bfe9c55059033
>>> import numpy
>>> D = numpy.array([[1, 0, 1, 0], [1, 0, 0, 0], [0, 1, 1, 1], [1, 1, 1, 1], [0, 0, 0, 0]], dtype=numpy.int8)
>>> D
array([[1, 0, 1, 0],
[1, 0, 0, 0],
[0, 1, 1, 1],
[1, 1, 1, 1],
[0, 0, 0, 0]], dtype=int8)
>>> D.size
20
View sliding_window_sort.py
"""Efficient sliding-window sorting of time-series data in CSV file.
Demo for http://stackoverflow.com/a/42398981/68707
Tested on Python 3.5.
"""
import collections
import csv
import datetime
View thread_test.py
"""Test how many threads we can run at once."""
import itertools
import threading
import time
import sys
import requests
View snakes_and_ladders.py
"""Calculate the average number of moves in a snakes and ladders game.
Because as a parent one gets roped into these board (boring?) games
every so often, and I wanted to calculate the average duration of a
snakes and ladders game. Turns out it's about 36 moves (though
admittedly that's for a single-player game). :-)
> python snakes_and_ladders.py
Played 10000 rounds, averaged 36.0559 moves, max 324 moves, took 0.508s
"""
View birthday_probability.py
"""Calculate the probability of generating a duplicate random number after
generating "n" random numbers in the range "d".
Usage: python birthday_probability.py n [d=365]
Each value can either be an integer directly, or in the format "2**x", where
x is the number of bits in the value.
For example, to calculate the probability that two people will have the same
birthday in a room with 23 people:
View atomic_counter.py
"""An atomic, thread-safe incrementing counter."""
import threading
class AtomicCounter:
"""An atomic, thread-safe incrementing counter.
>>> counter = AtomicCounter()
>>> counter.increment()
View generate_key.py
"""Function to generate a random string (key) of length chars."""
import binascii
import os
def generate_key(length=40, get_bytes=os.urandom):
"""Return a randomly-generated key of length chars.
>>> len(generate_key())
View ngrams.py
"""Print most frequent N-grams in given file.
Usage: python ngrams.py filename
Problem description: Build a tool which receives a corpus of text,
analyses it and reports the top 10 most frequent bigrams, trigrams,
four-grams (i.e. most frequently occurring two, three and four word
consecutive combinations).
NOTES
View gist:4044946
"""Speed up os.walk() significantly by using file attributes that
FindFirst/Next give us instead of doing an extra stat(). Can also do the same
thing with opendir/readdir on Linux.
This is doubly useful when the user (caller of os.walk) is doing *another*
stat() to get say the file sizes.
On my tests (Windows 64-bit) our walk() is about 5x as fast as os.walk() for
large directory trees, and 9x as fast if you're doing the file size thing.
Note that these timings are "once it's in the cache", not first-time timings.