4 ms·

I have sometimes wondered why python used 'lambda' for anonymous functions rather than just... well literally anonymous function - normal function syntax withou

• pyre 10y ago
  It's because lambda technically isn't an anonymous function. It's more like an anonymous expression. It probably helps to avoid confusion for people trying to do things that can't be expressions in it. E.g.: def (x,y): x += y
• nerdponx 10y ago
  I suspect this is because def f(x, y): x+y is valid one-line syntax for a regular function definition (that in this case computes `x+y` and returns `None` becaus Python does not have implicit returns). Maybe the parser could distinguish between them by saying that "if the function definition is all on one line and the function is missing its name, it's a lambda": def f(x,y): return x+y g = def x,y: x+y assert f(3,4) == g(3,4) assert f != g That said I have no Nothing gives me the willies in mathematical code like writing out Greek letters. I don't know why, it just does. The fact that the otherwise excellent Stan (https://mc-stan.org https://mc-stan.org) only accepts ASCII variable names is depressing. I would love to be able to actually write `map(λ x: x+7, range(5))`. I think a big reason why people don't use `map`/`reduce`/etc. more is that writing anonymous functions is still verbose (`lambda` is just too long a word) and relatively hard to read compared to list comprehension. Better still a syntax like `x -> x+7` would be ideal, since I'm pretty sure `->` would be a unique syntax element.