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> The error from "file" != b"file" is particularly bad. It makes sense if you realise that a == b means a,b have the same type and their values are equal. But there is no way a even a reasonably careful programmer could spot this without super careful testing (and who’s to say they would remember to test b"file" and not "file").

I'm of the opposite opinion. I appreciate that b'a' != 'a'.




I don’t think it’s a problem that they aren’t equal. This is reasonable. The problem is that it is hard for one to foresee this error. The mental model of bytes and strings is likely to be either their equal-looking literals or a mental concept of “bytes and strings are basically the same except for some exceptions.” One cannot reasonably trace every variable to figure out whether it is a bytes or a string. The comparison a == b being false comparing strings to bytes makes sense when a and b could be anything. However when b is already definitely a (byte) string, it is more useful to get an error when a has a different type.

What is your opinion on numbers:

Should 1 == 1.0?

What about 1+0j?

Or 1/1 (the rational number, although I’m not sure this can be constructed)?


int and float being comparable is practical, though occasionally troublesome. Complex usually doesn't compare well across types. You can use a Fraction type for 1/1. I haven't formed an opinion about that, since I don't use them often.




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