🔒 defining intervals

[fast helm]

not sure how to go about defining equalities, intersections, and differences. I keep getting assertion or type errors.

note: class Interval cannot be edited

[dense dust]

@fast helm

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[obtuse surge]

don't use &

Use and

[obtuse surge]

You're not comparing properly

Do one comparison individually

Interval(3,10) == Interval(6,10)

But I don't think you're using either functions properly

[fast helm]

how would i use the functions properly?

[obtuse surge]

You call them

oh wait you're overloading the methods

then it should be fine

Do individual comparisons

[sand gull]

You need to parenthesize since == has higher precedence than 'and'

assert (Interval1 and Interval2) == Interval3

[obtuse surge]

no you have to compare individually

like this

assert Interval(3,10) == Interval(6,10)

[sand gull]

Do you also have a custom equal comparator?

[obtuse surge]

If you want to compare both at the same time, you can add and after that

assert Interval(3,10) == Interval(6,10) and Interval(6,20) == Interval(6,10)

[sand gull]

(i.e. Did you override __eq__)

[obtuse surge]

OP did

[sand gull]

No, he wants to get the intersection of both, so using 'and' is correct .

[blazing dagger]

U sure that indent is right?

You return before it can reach Interval.__eq__ = func

[sand gull]

Your interval equality check seems strange. It only checks if the other interval is an Interval.

You should be checking if the endpoints are equal too?

[sand gull]

Oh good catch.

[fast helm]

the parts that say test were written by the prof to grade the def, not sure if i am allowed to edit those or why they are the way they are

[fast helm]

how do i fix this?

[blazing dagger]

Unindent?
The others funcs don't seem like they have this issue

[sand gull]

Wait, then the test is correct, it should be bitwise and (&) instead of logical and (and)

[blazing dagger]

I'd assume you're meant to change those def, then if you pass the tests you get the points

[sand gull]

No need to parenthesize now, but change the asserts back to use bitwise and (&)

[sand gull]

Dunder __and__ overrides bitwise and

[sand gull]

Now the problem is that your equality check doesn't work

As I said, you need to do more than just test for 'other' being an Interval.

Two intervals are equal if and only if their corresponding endpoints are equal.

Also, make sure you have overridden dunder __ne__

(as a shortcut, you can define __ne__ using __eq__)

[blazing dagger]

__ne__

[sand gull]

Oh my bad

[blazing dagger]

But you don't have to, it uses the inverted result of eq by default

[sand gull]

It does?!

That's news to me, thank you

[blazing dagger]

Anyway,
now it's correctly setting the funcs, now change the defs so the tests pass

[sand gull]

Is this also true for say lt and ge?

If so, what's the 'minimum' that I need to override?

Or any docs I can read about this?

[fast helm]

ok tysm i appreciate y'all so much

!close

[dense dust]

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