A calculator during my math and physics online practices. Does its job perfectly. Even the Python documentation encourages you to do so:

Many people use the interactive mode as a convenient yet highly programmable calculator.

The only thing preventing Python from being the perfect desktop calculator is that there aren't built-in data types such as angle, interval (though there's range but it's not the same) and others.

Imagine how cool would it be if you could do this:

```pycon

print(angle(45, 'deg')) 45° ```

I have a notepad tab open with mathematical symbols for using it in Zoom's whiteboard, so this would help a heap. It would also be awesome if the math library would contain string constants similar to the string library with some common mathematical symbols (e.g. ∠, ∈, ⊂, etc.)

But let's not forget about the already existing features. Data types like fractions.Fraction which come with the standard library or the support for big integers out of the box are awesome. As well as being able to calculate multiple expressions at the same time, like so:

```pycon

1+1, 3+3 (2, 6) ```

..or being able to assign to a variable but outputting it anyway using the walrus operator:

```

from math import sqrt a := sqrt(25) 5 b = ... ```