In Julia, how do I find out why Dict{String, Any} is Any?

Question

I am very new to Julia and mostly code in Python these days. I am using Julia to work with and manipulate HDF5 files.

So when I get to writing out (h5write), I get an error because the data argument is of mixed type and I need to find out why.

The error message says Array{Dict{String,Any},4} is what I am trying to pass in, but when I look at the values (and it is a huge structure), I see a lot of 0xff and values like this. How do I quickly find why the Any and not a single type?

Answer 1

Just to make this an answer:

If my_dicts is an Array{Dict{String, Any}, 4}, then one way of working out what types are hiding in the Any part of the dict is:

unique(typeof.(values(my_dicts[1])))

To explain:

• my_dicts[1] picks out the first element of your Array, i.e. one of your Dict{String, Any}
• values then extracts the values, which is the Any part of the dictionary,
• typeof. (notice the dot) broadcasts the typeof function over all elements returned by values, returning the types of all of these elements; and
• unique takes the list of all these types and reduces it to its unique elements, so you'll end up with a list of each separate type contained in the Any partof your dictionary.