def sortHeaderNames(headerNames):
 headers = [a.strip() for a in headerNames.split(',') if a.strip()]
 headers.sort()
 return ', '.join(headers)

def sortHeaderNames ( headerNames ) : headers = [ a . strip ( ) for a in headerNames . split ( ',' ) if a . strip ( ) ] headers . sort ( ) return ', ' . join ( headers )
return the given string of header names sorted .