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Ways to implement data versioning in MongoDB

...nt contain a dictionary of time-stamped diffs. Something like this: { _id : "id of address book record", changes : { 1234567 : { "city" : "Omaha", "state" : "Nebraska" }, 1234568 : { "city" : "Kansas City", "state" : "Missouri" } } } To make...
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Getting a map() to return a list in Python 3.x

...o be ASCII/latin-1 is to do bulk conversions at the C layer: bytes(sequence_of_ints_in_range_0_to_256).decode('latin-1') which makes a str faster by avoiding Python function calls for each element in favor of a bulk conversion of all elements using only C level function calls. You can wrap the above...
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Is there a way to detach matplotlib plots so that the computation can continue?

...rocessing import Process from matplotlib.pyplot import plot, show def plot_graph(*args): for data in args: plot(data) show() p = Process(target=plot_graph, args=([1, 2, 3],)) p.start() print 'yay' print 'computation continues...' print 'that rocks.' print 'Now lets wait for the g...
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Coding Practices which enable the compiler/optimizer to make a faster program

...ovide an example of loop unrolling Before: unsigned int sum = 0; for (size_t i; i < BYTES_TO_CHECKSUM; ++i) { sum += *buffer++; } After unrolling: unsigned int sum = 0; size_t i = 0; **const size_t STATEMENTS_PER_LOOP = 8;** for (i = 0; i < BYTES_TO_CHECKSUM; **i = i / STATEMENTS_PER_L...
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JavaScript is in array

...if the result > -1 and false if result === -1 – bm_i Nov 5 '12 at 19:01 11 @bm_i Which faster?...
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instantiate a class from a variable in PHP?

...you work with namespace, put the current namespace into the string: $var = __NAMESPACE__ . '\\' . $var . 'Class'; – bastey Sep 2 '13 at 13:28 ...
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PHP check whether property exists in object or class

... property_exists( mixed $class , string $property ) if (property_exists($ob, 'a')) isset( mixed $var [, mixed $... ] ) if (isset($ob->a)) isset() will return false if property is null Example 1: $ob->a = null var_du...
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How to download image using requests

...flate). You can force it to decompress for you anyway by setting the decode_content attribute to True (requests sets it to False to control decoding itself). You can then use shutil.copyfileobj() to have Python stream the data to a file object: import requests import shutil r = requests.get(settin...
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Remove characters except digits from string using Python?

...ion of "everything but" a few characters: import string class Del: def __init__(self, keep=string.digits): self.comp = dict((ord(c),c) for c in keep) def __getitem__(self, k): return self.comp.get(k) DD = Del() x='aaa12333bb445bb54b5b52' x.translate(DD) also emits '1233344554552'. ...
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How can I get the current screen orientation?

... This only provides two values ORIENTATION_PORTRAIT and ORIENTATION_LANDSCAPE. Is there a way to get all the four values from ActivityInfo? (That is LANDSCAPE_REVERSE and PORTRAIT_REVERSE as well) – HRJ May 4 '11 at 9:56 ...