Error when getting columns on PyPandasDataFrame

[nardi]

When running the following example code:

using PythonCall
using Tables

@pyg `
import numpy as np
import pandas as pd

$x = pd.DataFrame(np.array((100, 100)))`

# Make sure the columns are strings, or it will fail in any case.
@pyg `$x.columns = map(str, $x.columns)`

y = PyPandasDataFrame(x)
Tables.columns(y)

I get the error:

ERROR: LoadError: map is not defined on sets
Stacktrace:
 [1] error(s::String)
   @ Base .\error.jl:33
 [2] map(f::Type, #unused#::Base.KeySet{String, PyPandasDataFrame})
   @ Base .\abstractarray.jl:2326
 [3] columns(x::PyPandasDataFrame)
   @ PythonCall [,,,]\.julia\packages\PythonCall\MBkDb\src\PyPandasDataFrame.jl:155

This could be fixed by changing the map call on line 155 to map(Symbol, collect(keys(x))) instead.

[cjdoris]

Thanks, now fixed on master.