I've been wandering for a while in the docs and in forums and I haven't found a built in method/function to do the simple task of deleting an element in an array. Is there such built-in function?
I am asking for the equivalent of python's list.remove(x).
Here's an example of naively picking a function from the box:
julia> a=Any["D","A","s","t"]
julia> pop!(a, "s")
ERROR: MethodError: `pop!` has no method matching
pop!(::Array{Any,1}, ::ASCIIString)
Closest candidates are:
pop!(::Array{T,1})
pop!(::ObjectIdDict, ::ANY, ::ANY)
pop!(::ObjectIdDict, ::ANY)
...
Here mentions to use deleteat!
, but also doesn't work:
julia> deleteat!(a, "s")
ERROR: MethodError: `-` has no method matching -(::Int64, ::Char)
Closest candidates are:
-(::Int64)
-(::Int64, ::Int64)
-(::Real, ::Complex{T<:Real})
...
in deleteat! at array.jl:621
You can also go with filter!
:
a = Any["D", "A", "s", "t"]
filter!(e->e≠"s",a)
println(a)
gives:
Any["D","A","t"]
This allows to delete several values at once, as in:
filter!(e->e∉["s","A"],a)
Note 1: In Julia 0.5, anonymous functions are much faster and the little penalty felt in 0.4 is not an issue anymore :-) .
Note 2: Code above uses unicode operators. With normal operators: ≠
is !=
and e∉[a,b]
is !(e in [a,b])