how to use _ in a function

[laocan]

I've try :
print math.sin(_)
it turn out to be wrong, but it works for:
lambda x: math.sin(x)

Does _ always be same as lambda caluse?
any limitation?
thx ~~

[kachayev]

@laocan There is no way in Python to work with expressions like math.sin(_) cause of evaluation order. And, btw, there is no necessity for doing this in you example. math.sin(_) most probably means lambda x: math.sin(x) which is equivalent to math.sin.

[microamp]

I would also like to suggest having a look at the tests. It does cover most of operators (e.g. operator.add). It also handles method calls as well as some neat stuff like slices!

[kachayev]

BTW, If you need to express math.ldexp(10, _) use partial(math.ldexp, 10). If you need math.ldexp(_, 10) use partial(flip(math.ldexp), 10).

Is there something else that I can help you with?

[laocan]

I got it.
thx~