Using add on int and str types in Python

Asked Aug 28 '20 at 13:44

Active Aug 28 '20 at 14:03

Viewed 61 times

I am trying to understand why the following code provides two different outcomes:

int(5).__add__(str(5))

Returns

NotImplemented

Shouldn't it then this return NotImplemented as well?

a = int(5)
b = str(5)
a+b

TypeError: unsupported operand type(s) for +: 'int' and 'str' While

5 + '5'

Returns

TypeError: unsupported operand type(s) for +: 'int' and 'str'

So it knows that the first 5 is an int type but can't use it on 5.__add__(5)

Does int class gets initialized differently when I assign an int to a variable rather than just using an int right away and treats objects differently when used in parentheses?

edited Aug 28 '20 at 13:56

asked Aug 28 '20 at 13:44

Jonas Palačionis

4,591
4
22
55

3

Because after `5.` the parser assumes you're writing a floating point number and expects another digit... See e.g. https://stackoverflow.com/q/31037609/3001761. – jonrsharpe Aug 28 '20 at 13:45
@jonrsharpe You can follow it with non-digits, though, for example `5.and(4)` happily gets evaluated to `4`. – superb rain Aug 28 '20 at 13:49
Thanks, that answers the first bit, any idea on the second part? – Jonas Palačionis Aug 28 '20 at 13:49
@superbrain because it's interpreted as `5. and 4` – jonrsharpe Aug 28 '20 at 13:50
3

What second part? [Edit] your post to ask a single clear question. – jonrsharpe Aug 28 '20 at 13:51
3

Please ask a new question; the original has already been closed as a separate question, and the edit is a *completely* separate question. – chepner Aug 28 '20 at 14:00
1

Are you really asking why `(5).__add__("5")` doesn't do the same as `5 + "5"`? You seem to have several confounding things right now. That would be a duplicate of e.g. https://stackoverflow.com/q/54775946/3001761. – jonrsharpe Aug 28 '20 at 14:00
Thank you all for your inputs, appreciated it. – Jonas Palačionis Aug 28 '20 at 14:04

Using __add__ on int and str types in Python

0 Answers0

Using add on int and str types in Python