[Edu-sig] Equality and Assignment Notation

[Josh McKenzie]

Hi

Why does Python use the equal sign (=) to mean assignment, and use
two equal signs (==) to mean equality? Equality and assignment are
not the same, yet the meaning of the equal sign is universally
understood, so why redefine its meaning?

I know other languages like Java and C++ employ this convention too,
but how does one explain the logic behind this approach?

I'll readily admit to a bias: when I see the notation ':=' in
languages like Pascal, Smalltalk or Eiffel etc, I can at least
understand the distinction these languages attempt to impart to the
user that equality and assignment are similar, but distinct concepts.

It may seem a trivial point to bring up, but while I can explain the
difference between equality and assignment, I cannot explain the
logic of using the '=' and '==' notation.

Thanks :-)

Regards - Josh M.

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