Python: Unexpected behaviour of nonlocal variable in recursion Question: The following code is expected to set the nonlocal variable flag to true after 3 calls to recur(). I expect flag in the following code to be always true after recur(2) returns (starting from 0) def f(): flag = False def recur(n): nonlocal flag print(f"this is …
Short-circuiting with helper function in print() Question: Can someone please explain why the following code comes out as "geeks" in the console? def check(): return "geeks" print(0 or check() or 1) I’m assuming that Python recognizes the boolean operator, thus treating 0 == False? So does that mean every time boolean operators are used, the …
Any/All python short-circuit: Why doesn't the following work? Question: Based on what I’ve seen on other stackoverflow pages: Does Python's `all` function use short circuit evaluation? Do all() and any() always short-circuit in order? Is the shortcircuit behaviour of Python's any/all explicit? the following code should short circuit: any([True, 2+2, False, 2/0]) all([True, 2+2, False, …
Does Python's `all` function use short circuit evaluation? Question: I wish to use the Python all() function to help me compute something, but this something could take substantially longer if the all() does not evaluate as soon as it hits a False. I’m thinking it probably is short-circuit evaluated, but I just wanted to make …
Is the shortcircuit behaviour of Python's any/all explicit? Question: Prompted by the discussion here The docs suggest some equivalent code for the behaviour of all and any Should the behaviour of the equivalent code be considered part of the definition, or can an implementation implement them in a non-shortcircuit manner? Here is the relevant excerpt …
How to prevent short-circuit evaluation? Question: This is a problem that occurred to me while working on a Django project. It’s about form validation. In Django, when you have a submitted form, you can call is_valid() on the corresponding form object to trigger the validation and return a Boolean value. So, usually you have code …
Where are the ampersand and vertical bar characters used in Python? Question: In the Wikipedia page describing short-circuit evaluation, & and | are listed as eager operators in Python. What does this mean and when are they used in the language? Asked By: Yktula || Source Answers: It means the left operand and the right …
Does Python support short-circuiting? Question: Does Python support short-circuiting in boolean expressions? Asked By: Dinah || Source Answers: Yep, both and and or operators short-circuit — see the docs. Answered By: Alex Martelli Short-circuiting behavior in operator and, or: Let’s first define a useful function to determine if something is executed or not. A simple …
