I wonder if it is necessary to add two new operators, and for me, "arrow
operator" is not clearer than `+`. Could you explain why do you prefer this
operator than `+`?
Also -> is a symbol of propositional logic, like ∧ and ∨ , do we also need
these operators as well?
At 2019-03-03
I think "Current Alternatives" section must refer to long existing idiom,
in addition to {**d1, **d2}:
d3 = d1.copy()
d3.update(d2)
It is obvious nor easily discoverable, while it takes two lines.
"There are no obvious way" and "there is at least one obvious way" is
very different.
On
I propose that the + sign merge two python dictionaries such that if there are
conflicting keys, a KeyError is thrown.
This way, d1 + d2 isn’t just another obvious way to do {**d1, **d2}. The second
syntax makes it clear that a new dictionary is being constructed and that d2
overrides keys
On Sun, Mar 03, 2019 at 03:46:24PM +0100, francismb wrote:
> Hi,
> the idea here is just to add the __larrow__ and __rarrow__ operators for
> <- and ->.
You cannot create operator ``<-`` because it's currently valid
syntax:
3 <- 2
is equivalent to
3 < -2
> Regards,
> --francis
Hi,
the idea here is just to add the __larrow__ and __rarrow__ operators for
<- and ->.
E.g. of use on dicts :
>>> d1 = {'a':1, 'b':1 }
>>> d2 = {'a':2 }
>>> d3 = d1 -> d2
>>> d3
{'a':1, 'b':1 }
>>> d1 = {'a':1, 'b':1 }
>>> d2 = {'a':2 }
>>> d3 = d1 <- d2
>>> d3
{'a':2, 'b':1 }
Or on bools as
On 2/27/19 7:14 PM, MRAB wrote:
> Are there any advantages of using '+' over '|'?
or '<-' (d1 <- d2) meaning merge priority (overriding policy for equal
keys) on the right dict, and may be '->' (d1 -> d2) merge priority on
the left dict over '+' (d1 + d2) ?
E.g.:
>>> d1 = {'a':1, 'b':1 }
>>> d2
On 3/2/19 11:11 PM, MRAB wrote:
> '<=' is for comparison, less-than-or-equal (in the case of sets, subset,
> which is sort of the same kind of thing). Using it for anything else in
> Python would be too confusing.
Understandable, so the the proposed (meaning) overloading for <= is also
too
