Question

I have this code:

filenames=["file1","FILE2","file3","fiLe4"]


def alignfilenames():
    #build a string that can be used to add labels to the R variables.
    #format goal: suffixes=c(".fileA",".fileB")
    filestring='suffixes=c(".'
    for filename in filenames:
        filestring=filestring+str(filename)+'",".'

    print filestring[:-3]
    #now delete the extra characters
    filestring=filestring[-1:-4]
    filestring=filestring+')'
    print "New String"
    print str(filestring)

alignfilenames()

I’m trying to get the string variable to look like this format: suffixes=c(".fileA",".fileB".....) but adding on the final parenthesis is not working. When I run this code as is, I get:

suffixes=c(".file1",".FILE2",".file3",".fiLe4"
New String
)

Any idea what’s going on or how to fix it?

Answer 1

Does this do what you want?

>>> filenames=["file1","FILE2","file3","fiLe4"]
>>> c = "suffixes=c(%s)" % (",".join('".%s"' %f for f in filenames))
>>> c
'suffixes=c(".file1",".FILE2",".file3",".fiLe4")'

Using a string.join is a much better way to add a common delimiter to a list of items. It negates the need to have to check for being on the last item before adding the delimiter, or in your case attempting to strip off the last one added.

Also, you may want to look into List Comprehensions