Sure, so I need col #1 in my CSV to be a string in my data frame. So as a test I tried to load the file 3 different ways:
*df1_CSV = CSV.read("$df1_path"; types=Dict(1=>String)) #forcing the column to stay a string* *df1_readtable = readtable("$df1_path") #Do not know how to force the column to stay a string* *df1_convertDF = convert(DataFrame, df1_CSV)* Here is the output: If they are all dataframes then showcols should work an all three df1: *julia> names(df1_CSV)* 3-element Array{Symbol,1}: :account_number Symbol("Discharge Date") :site *julia> names(df1_readtable)* 3-element Array{Symbol,1}: :account_number :Discharge_Date :site *julia> names(df1_convertDF)* 3-element Array{Symbol,1}: :account_number Symbol("Discharge Date") :site *julia> eltypes(df1_CSV)* 3-element Array{Type,1}: Nullable{String} Nullable{WeakRefString{UInt8}} Nullable{WeakRefString{UInt8}} *julia> eltypes(df1_readtable)* 3-element Array{Type,1}: Int32 *#Do not know how to force the column to stay a string* String String *julia> eltypes(df1_convertDF)* 3-element Array{Type,1}: Nullable{String} Nullable{WeakRefString{UInt8}} Nullable{WeakRefString{UInt8}} *julia> showcols(df1_convertDF)* 1565x3 DataFrames.DataFrame ERROR: MethodError: no method matching countna(::NullableArrays.NullableArray{St ring,1}) Closest candidates are: countna(::Array{T,N}) at C:\Users\lmathews\.julia\v0.5\DataFrames\src\other\ut ils.jl:115 countna(::DataArrays.DataArray{T,N}) at C:\Users\lmathews\.julia\v0.5\DataFram es\src\other\utils.jl:128 countna(::DataArrays.PooledDataArray{T,R<:Integer,N}) at C:\Users\lmathews\.ju lia\v0.5\DataFrames\src\other\utils.jl:143 in colmissing(::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0.5\DataFram es\src\abstractdataframe\abstractdataframe.jl:657 in showcols(::Base.TTY, ::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0. 5\DataFrames\src\abstractdataframe\show.jl:574 in showcols(::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0.5\DataFrames \src\abstractdataframe\show.jl:581 *julia> showcols(df1_readtable)* 1565x3 DataFrames.DataFrame │ Col # │ Name │ Eltype │ Missing │ ├───────┼────────────────┼────────┼─────────┤ │ 1 │ account_number │ Int32 │ 0 │ │ 2 │ Discharge_Date │ String │ 0 │ │ 3 │ site │ String │ 0 │ *julia> showcols(df1_CSV)* 1565x3 DataFrames.DataFrame ERROR: MethodError: no method matching countna(::NullableArrays.NullableArray{St ring,1}) Closest candidates are: countna(::Array{T,N}) at C:\Users\lmathews\.julia\v0.5\DataFrames\src\other\ut ils.jl:115 countna(::DataArrays.DataArray{T,N}) at C:\Users\lmathews\.julia\v0.5\DataFram es\src\other\utils.jl:128 countna(::DataArrays.PooledDataArray{T,R<:Integer,N}) at C:\Users\lmathews\.ju lia\v0.5\DataFrames\src\other\utils.jl:143 in colmissing(::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0.5\DataFram es\src\abstractdataframe\abstractdataframe.jl:657 in showcols(::Base.TTY, ::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0. 5\DataFrames\src\abstractdataframe\show.jl:574 in showcols(::DataFrames.DataFrame) at C:\Users\lmathews\.julia\v0.5\DataFrames \src\abstractdataframe\show.jl:581 On Thursday, November 3, 2016 at 8:54:19 AM UTC-4, Michael Borregaard wrote: > > The result of CSV should be a DataFrame by default. What return type do > you get? >