Python's Walrus Operator??

Background Music:
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[xonxt]

An obvious note is that the Walrus Operator only appeared since Python 3.8, so if you have to work on older systems, it will not be backwards compatible...

[finnthirud]

I love that you added the "obvious" method which makes for a great explanation of when to choose what, i.e. readability. Great tutoring. Thank you! :=

[foreverunsure]

wow, this was an easy and straight to the point explanation, thank you!

[AetherBreaker]

Something worth noting about the walrus operator, is that it always "returns" the value of the variable, unlike a regular assignment operation (eg: x = 10), this is why it works inside stuff like an if statement or inside other operations.

In python, you have assignments, and expressions, you can assign an expression to something, but you cannot perform a normal assignment inside an expression because a normal assignment doesnt return anything.

[nicktreleaven]

Another nice example from the PEP with while:

while chunk := file.read(8192):
process(chunk)

You can't rewrite that without having to change the control flow.

[davidking]

Historical note from an old-timer:
We never thought to call it "the walrus operator" but . . .
Going back DECADES the := operator was used in Algol and derived languages (like Pascal) . . . for assignment statements.

[christosmantas]

I really like these style of `if` predicates and did not know about this operator.
Thanks

[rask]

This is interesting to know and I appreciate how such syntactic sugars are useful. Also, I've encountered many situations where the use of such specific or unique syntax make reading the code more effort-full, which especially in teams and with team communication can slow development. Personally, if it can be done in a way which is faster to comprehend without major impacts to other aspects of the development cycle or to product maintenance, then that way is preferable.

Also, I cannot get the similarity of a C-syntax variable assignment inside a control structure's condition evaluation out of my head.

[stefaanverstraeten]

Anybody else remembers this as the standard assign statement from Pascal?

[turglow]

exactly what i was looking for, thanks

[scaffus]

My god I've been missing out on this one, thank you very much

[lirsanplay]

I like what i saw on your channel so far.
I suggest video about lambda functions. Especially in list comprehintion.
For me, at was always something strange, what i forget every time i learn it.

[AdityaSharma-wgrj]

nice way to explain is such a easy manner

[nicktreleaven]

It can also avoid indentation. Before:
match1 = pattern1.match(data)
if match1:
result = match1.group(1)
else:
match2 = pattern2.match(data)
if match2:
result = match2.group(2)
else:
result = None
After:
if match1 := pattern1.match(data):
result = match1.group(1)
elif match2 := pattern2.match(data):
result = match2.group(2)
else:
result = None

Example from the PEP.

[GuagoFruit]

I used to do this a lot in C, but forgot that it exists in Python so thanks for reminding me.

[basharat]

Can someone tell me why my VS code doesn't show the result directly but show extra details of the folder and stuff before giving the output ?

[cleverclover]

Seeing as you had to make a video to explain what it does I would argue assigning to the variable is more easily understood. Good video.

[fllthdcrb]

I didn't know something like this was in Python. Very interesting. This is very similar to the "=" operator in C, except that can be used for assignment anywhere in an expression, including something that looks like Python's assignment statements. The problem with that is it's quite easy to accidentally turn the equality operator "==" into the assignment operator, especially in conditions, where it will cause an assignment and make the condition succeed when it shouldn't. It's good practice to use parentheses to make deliberate embedded assignments clear, and some compilers can detect if you don't. But I like this approach, of requiring you to write a different operator if you really mean to do this.

[tinypus]

Dude I'm a freshman taking APSCP, our teacher is teaching VIA python. I've picked up on it fast, but a lot of advanced stuff like this is hard for me (Especially since we're working on AP task). I really appreciate the tricks and tips you provide!

[NowLP]

fascinating, I have wondered if something like this exists in python, since it does in e.g. Swift and theoretically Rust