error with @rename macro

[pstaabp]

If we use:

using Query, DataFrames
df = DataFrame(a=[1,2,3],b=["a","b","c"])

The command:

df |> @rename(:a=>:d)

does the expected rename of the column, however if:

df |> @rename(Symbol("a") => :d)

returns the error:

MethodError: no method matching getindex(::Nothing, ::Int64)

Stacktrace:
 [1] @rename(::LineNumberNode, ::Module, ::Vararg{Any,N} where N) at /Users/XXX/.julia/packages/Query/AwBtd/src/table_query_macros.jl:149

but I would expect the same result. I'm using Julia 1.4.1 and Query 0.12.2.

The reason for doing this would be to rename columns with spaces in them.

[danvinci]

Running into the same issue while working with data frames, in some cases using Symbol is mandatory as the column name includes numbers or things like % or ‰.

@pstaabp if it might help, this is my current workaround:

I defined a function to replace characters preventing column names (in my case) being interpreted as symbols:

function tidy_names(old_names)

  return new_names = old_names |>
  #replace spaces with underscores
  n -> replace.(n, ' ' => '_') |> 

  #remove parenthesis
  n -> replace.(n,'(' => "") |> 
  n -> replace.(n,')' => "") |>

  #remove dashes and dots
  n -> replace.(n,'-' => "") |> 
  n -> replace.(n, '.' => "") |>

  #all lowercase
  n -> lowercase.(n)

end

And then I run:

rename!(df ,names(df) .=> tidy_names(names(df)))

Before feeding the df to the pipe-magic that Query.jl allows.