python-internals Archives

Programming, Python

IT Nursery

Why can tuples contain mutable items?

If a tuple is immutable then why can it contain mutable items? It is seemingly a contradiction that when a mutable item such ...

June 1, 2022
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Programming, Python

IT Nursery

Finding the source code for built-in Python functions?

Is there a way to see how built in functions work in python? I don’t mean just how to use them, but also ...

May 31, 2022
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Programming, Python

IT Nursery

Accessing class variables from a list comprehension in the class definition

How do you access other class variables from a list comprehension within the class definition? The following works in Python 2 but fails ...

May 27, 2022
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What is the global interpreter lock (GIL) in CPython?

What is a global interpreter lock and why is it an issue? A lot of noise has been made around removing the GIL ...

May 20, 2022
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How does asyncio actually work?

This question is motivated by my another question: How to await in cdef? There are tons of articles and blog posts on the ...

May 20, 2022
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Why is ‘x’ in (‘x’,) faster than ‘x’ == ‘x’?

>>> timeit.timeit("'x' in ('x',)") 0.04869917374131205 >>> timeit.timeit("'x' == 'x'") 0.06144205736110564 Also works for tuples with multiple elements, both versions seem to grow linearly: ...

May 19, 2022
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Are tuples more efficient than lists in Python?

Is there any performance difference between tuples and lists when it comes to instantiation and retrieval of elements? 9 Answers 9

May 18, 2022
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Why are some float < integer comparisons four times slower than others?

When comparing floats to integers, some pairs of values take much longer to be evaluated than other values of a similar magnitude. For ...

May 18, 2022
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time.sleep — sleeps thread or process?

In Python for *nix, does time.sleep() block the thread or the process? 7 Answers 7

May 8, 2022
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