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How is Python's List Implemented?
Is it a linked list, an array? I searched around and only found people guessing. My C knowledge isn't good enough to look at the source code.
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How to get the return value from a thread in python?
...m) for param in param_list] The order will be maintained, and exiting the with will allow result collection. [f.result() for f in futures]
– jayreed1
Jun 4 at 21:29
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How do I center floated elements?
I'm implementing pagination, and it needs to be centered. The problem is that the links need to be displayed as block, so they need to be floated. But then, text-align: center; doesn't work on them. I could achieve it by giving the wrapper div padding of left, but every page will have a different ...
pandas GroupBy columns with NaN (missing) values
...the same placeholder hack).
However, as described in another answer, from pandas 1.1 you have better control over this behavior, NA values are now allowed in the grouper using dropna=False
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How to generate all permutations of a list?
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Starting with Python 2.6 (and if you're on Python 3) you have a standard-library tool for this: itertools.permutations.
import itertools
list(itertools.permutations([1, 2, 3]))
If you're using an older Python (<2.6) for some reason or are just...
Which version of Python do I have installed?
...script on a Windows server. How can I know which version of Python I have, and does it even really matter?
22 Answers
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Confused about __str__ on list in Python [duplicate]
Coming from a Java background, I understand that __str__ is something like a Python version of toString (while I do realize that Python is the older language).
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How can I tell Rails to use RSpec instead of test-unit when creating a new Rails app?
I have test-unit installed and rspec installed (along with -core , -expectations , -mocks and -rails version 2.6.x). When I run the command rails new foo , it uses test-unit to generate the test stub files instead of rspec .
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ERROR: Error 1005: Can't create table (errno: 121)
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I searched quickly for you, and it brought me here. I quote:
You will get this message if you're trying to add a constraint with a
name that's already used somewhere else
To check constraints use the following SQL query:
SELECT
constraint_n...
Reusing output from last command in Bash
Is the output of a Bash command stored in any register? E.g. something similar to $? capturing the output instead of the exit status.
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