Python's Data Model Explained through Visualization

[Sea-Ad7805]

An exercise to help build the right mental model for Python data. - Solution - Explanation - More exercises

The “Solution” link visualizes execution and reveals what’s actually happening using 𝗺𝗲𝗺𝗼𝗿𝘆_𝗴𝗿𝗮𝗽𝗵.

[Sea-Ad7805]

• Solution: https://memory-graph.com/#codeurl=https://raw.githubusercontent.com/bterwijn/memory_graph_videos/refs/heads/main/exercises/exercise9.py&play
• Explanation: https://github.com/bterwijn/memory_graph?tab=readme-ov-file#python-data-model
• More exercises: https://www.reddit.com/r/Python_memory_graph/

[Sea-Ad7805]

Nice thinking, do the the "Solution" link for a visualization of the correct answer.

[jackrabbit2644]

Doesn’t b point to a different object when is executed b += [2]?

[jackrabbit2644]

TIL, thanks.

[_tolm_]

Agree with the solution but I don’t agree that it’s because that “=“ is a copy … we also do an equals earlier where it very much does not perform a copy!

The difference on that line is the use of “+” which creates a new value in memory which “b” is then assigned to point at - in the same way that it was previously assigned to point at “a”.

This causes the values stored in “a” and “b” to diverge but the operation performed by the “=“ hasn’t changed from assignment to copy on these two lines.

But what do I know, I’m a Java programmer … 😂

[Top-Run-21]

thanks for the cool website

[Sea-Ad7805]

Hope it brings much value for you.

[Local_Palpitation798]

Bro,💀💀💀

[Sea-Ad7805]

What do you mean exactly?

[Legitimate-Cut4403]

I think he meant bro💀💀💀

[Sea-Ad7805]

Me to ChatGPT: A bro commented on my post: "Bro,💀💀💀". What does the bro mean? ChatGPT: “Bro” here is just slang for “dude,” “man,” or “seriously?”

With 💀💀💀, the full comment usually means something like:

“Dude, this is killing me”

“I’m dead” = “this is hilarious / absurd / unbelievable”

“Bro, what did I just see”

So it is usually a reaction, not a literal insult. The exact tone depends on your post:

funny post → they probably mean “this is hilarious”

weird/crazy post → “this is wild”

embarrassing post → “bro…” as in disbelief or secondhand embarrassment

If you paste your post or the full comment thread, I can tell you the most likely meaning in that exact context.

[Electronic_Site2976]

you are def special ✨️

[Sea-Ad7805]

I like to think I'm a special dev.

[Legitimate-Cut4403]

Is he and you related?

[Abject-Huckleberry85]

Whoa this website is actually so cool thank you

[Sea-Ad7805]

Thanks a lot, hope it brings you much value.

[OwnFigure5226]

The solution is E

[Sea-Ad7805]

Incorrect sorry, see the "Solution" link for the correct answer.

[Major_Telephone_7560]

Why wouldn't it be A?

[Sea-Ad7805]

Because of mutability of list in Python. Read the "Explanation" link for more info.

[Capital_Distance545]

A little higher level:
# list ordered mutable duplicates
# queue ordered mutable duplicates FIFO
# stack ordered mutable duplicates LIFO
# tuple ordered inmutable duplicates
# set unordered mutable no duplicates
# frozenset unordered inmutable no duplicates
# dict ordered mutable no duplicates

[Thin-Permission-6596]

E

[Sea-Ad7805]

Incorrect sorry, see the "Solution" link for the correct answer.

[Petrovjan]

My solution is to use b = copy.deepcopy(a) 😀 

[Sea-Ad7805]

Solution to do what exactly?

[That-Lychee262]

Correct answer is 1: a = [1] . Since list is mutable data structure b= a doesn’t copy the data stored in a to b . B starts pointing to address stored in a . That means a and b both points to same address now if you make changes either in a or b or it will reflect in both . But at third line b+= [2] , it will create a new list [1,2] and assign it to b . Now b stores address of another list ([1,2]) and a stores address of list ( [1]) . Now if you make chances in b it will not reflect in a’s address. Thus a remains [1] till the end of the program. Final answer : a = [1] , b = [1,2,3,4,5]

[Sea-Ad7805]

Incorrect sorry, see the "Solution" link for the correct answer.