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What is the syntax rule for having trailing commas in tuple definitions?
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In all cases except the empty tuple the comma is the important thing. Parentheses are only required when required for other syntactic reasons: to distinguish a tuple from a set of function arguments, operator precedence, or to a...
How to write a Python module/package?
I've been making Python scripts for simple tasks at work and never really bothered packaging them for others to use. Now I have been assigned to make a Python wrapper for a REST API. I have absolutely no idea on how to start and I need help.
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Python list of dictionaries search
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Is worth noting that this answer returns a list with all matches for 'Pam' in people, alternatively we could get a list of all the people that are not 'Pam' by changing the comparison operator to !=. +1
– Onema
Nov 12 '15 at 22:25
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Generate a heatmap in MatPlotLib using a scatter data set
...50 heatmap. If you want, say, 512x384, you can put bins=(512, 384) in the call to histogram2d.
Example:
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List of lists changes reflected across sublists unexpectedly
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When you write [x]*3 you get, essentially, the list [x, x, x]. That is, a list with 3 references to the same x. When you then modify this single x it is visible via all three references to it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 1405608979...
Flatten nested dictionaries, compressing keys
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Basically the same way you would flatten a nested list, you just have to do the extra work for iterating the dict by key/value, creating new keys for your new dictionary and creating the dictionary at final step.
import collectio...
StringBuilder vs String concatenation in toString() in Java
...o builder?
At the point where you're concatenating in a loop - that's usually when the compiler can't substitute StringBuilder by itself.
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How to use the IEqualityComparer
I have some bells in my database with the same number. I want to get all of them without duplication. I created a compare class to do this work, but the execution of the function causes a big delay from the function without distinct, from 0.6 sec to 3.2 sec!
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Multiple levels of 'collection.defaultdict' in Python
...ng specific that you need help with? When d[new_key] is accessed, it will call the lambda which will create a new defaultdict(int). And when d[existing_key][new_key2] is accessed, a new int will be created.
– interjay
Oct 11 '13 at 12:53
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round() for float in C++
... but there are others such as round-to-even, which is less biased and generally better if you're going to do a lot of rounding; it's a bit more complex to implement though.
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