Oct 24, 2011 · If one line code is definitely going to happen for you, Python 3.8 introduces assignment expressions affectionately known as “the walrus operator”. someBoolValue and (num := 20) The 20 will be assigned to num if the first boolean expression is True .

May 6, 2015 · For Python 3.8+, PEP 572 introduces Assignment Expressions This allows assigning to variables within an expression using the notation NAME := expr . It can be used within if statements, for example:

Apr 27, 2019 · The one liner doesn't work because, in Python, assignment (fruit = isBig(y)) is a statement, not an expression. In C, C++, Perl, and countless other languages it is an expression, and you can put it in an if or a while or whatever you like, but not in Python, because the creators of Python thought that this was too easily misused (or abused) to ...

May 22, 2020 · In the official Python documentation, the assignment = is referred to as a statement or an expression. I really don't get it what it means by assignment is a statement. How is assignment a statement?

Everybody knows that in Python assignments do not return a value, presumably to avoid assignments on if statements when usually just a comparison is intended: >>> if a = b: File "<st...

Jan 6, 2012 · I also feel a bit unconfortable using that kind of expressions. In Learning Python 4ed it is called a "somewhat unusual behavior". Later Mark Lutz says:...it turns out to be a fairly common coding paradigm in Python: to select a nonempty object from among a fixed-size set, simply string them together in an or expression.

Apr 8, 2010 · Note that in Python, unlike C, assignment cannot occur inside expressions. C programmers may grumble about this, but it avoids a common class of problems encountered in C programs: typing = in an expression when == was intended.

Since Python 3.8, code can use the so-called "walrus" operator (:=), documented in PEP 572, for assignment expressions. This seems like a really substantial new feature, since it allows this form of assignment within comprehensions and lambdas. What exactly are the syntax, semantics, and grammar specifications of assignment expressions?

Aug 22, 2015 · All target_list productions (i.e. things that look like foo =) in an assignment statement get assigned, from left to right, to the expression_list on the right end of the statement, after the expression_list gets evaluated. And of course the usual 'tuple-unpacking' assignment syntax works within this syntax, letting you do things like

Mar 21, 2023 · The code in the question is pseudo-code; there, := represents assignment. For future visitors, though, the following might be more relevant: the next version of Python (3.8) will gain a new operator, :=, allowing assignment expressions (details, motivating examples, and discussion can be found in PEP 572, which was provisionally accepted in late June 2018).