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How can I use threading in Python?
...ticle/blog post that you should definitely check out (no affiliation) - Parallelism in one line: A Better Model for Day to Day Threading Tasks. I'll summarize below - it ends up being just a few lines of code:
from multiprocessing.dummy import Pool as ThreadPool
pool = ThreadPool(4)
results = pool.m...
Update MongoDB field using value of another field
...
The best way to do this is in version 4.2+ which allows using of aggregation pipeline in the update document and the updateOne, updateMany or update collection method. Note that the latter has been deprecated in most if not all languages drivers.
MongoDB 4.2+
Version 4.2 ...
How to make an OpenGL rendering context with transparent background?
Rendering contexts usually have a solid color on the background (black or whatever, see the image below):
9 Answers
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Removing Data From ElasticSearch
...lasticSearch. I have deleted my indexes. However, that doesn't seem to actually remove the data itself. The other stuff I've seen points to the Delete by Query feature. However, I'm not even sure what to query on. I know my indexes. Essentially, I'd like to figure out how to do a
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Python ElementTree module: How to ignore the namespace of XML files to locate matching element when
I want to use the method of "findall" to locate some elements of the source xml file in the ElementTree module.
10 Answers
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Nested classes' scope?
...e will use that object the next time it is executed.)
If you instead want all Inner objects to have a reference to an Outer because outer_var is really an instance attribute:
class Outer(object):
def __init__(self):
self.outer_var = 1
def get_inner(self):
return self.Inner...
libpthread.so.0: error adding symbols: DSO missing from command line
...nd line after the object files being compiled:
gcc -Wstrict-prototypes -Wall -Wno-sign-compare -Wpointer-arith -Wdeclaration-after-statement -Wformat-security -Wswitch-enum -Wunused-parameter -Wstrict-aliasing -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-pr...
Add custom messages in assert?
...rk; they’re compile-time constants and their use in this context is trivially optimized away. There is no runtime cost.
– zneak
Aug 9 '19 at 8:46
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Why does running the Flask dev server run itself twice?
...g is the library that supplies Flask with the development server when you call app.run().
See the restart_with_reloader() function code; your script is run again with subprocess.call().
If you set use_reloader to False you'll see the behaviour go away, but then you also lose the reloading function...
What is a plain English explanation of “Big O” notation?
...a notation "Θ" (which is a two-side bound). In my experience, this is actually typical of discussions in non-academic settings. Apologies for any confusion caused.
Big O complexity can be visualized with this graph:
The simplest definition I can give for Big-O notation is this:
Big-O notation is ...