Reading CSV and FWF files

Reading comma-separated value (CSV) and fixed-width files (FWF) are commonly needed operations in data processing. In this recipe, we look at how Julia supports these operations.

 

Getting ready

Start the Julia command line and create two IOBuffer objects from which we'll read data:

julia> csv = """a,b,c
                11,2,3
                4,555,6
                7,8,9999"""
"a,b,c\n11,2,3\n4,555,6\n7,8,9999"

julia> iocsv = IOBuffer(csv)
IOBuffer(data=UInt8[...], readable=true, writable=false, seekable=true, append=false, size=29, maxsize=Inf, ptr=1, mark=-1)

julia> fwf = """a  b      c
                11 2      3
                4  555   66
                7  8   9999"""
"a b    c\n11 2    3\n4 555   66\n7 8 9999"

julia> iofwf = IOBuffer(fwf)
IOBuffer(data=UInt8[...], readable=true, writable=false, seekable=true, append=false, size=47, maxsize=Inf, ptr=1, mark=-1)

Note

In the GitHub repository for this recipe, you will find the commands.txt file, which...