On Thursday, March 17, 2016 at 10:09:27 PM UTC+5:30, Charles T. Smith wrote: > or something else ... you're in a "defend python at all costs!" mode.
Interesting that I see this now. I was showing some finance-friends how to to convert one of the tables in https://www.nyse.com/publicdocs/nyse/markets/amex-options/ArcaDirectAPISpecVersion4_1.pdf [printed page 9 pdf pg 12 "Equities Symbology" ] Since they were much more comfortable with perl than with python I wrote the first version in perl (which I am not comfortable with!): You try these by calling at command line with one argument such as IBM.A# The perl and python versions are not matching in output behavior but thats not really relevant; what we want is the exact recognition of that table (currently only a subset that I understand!) --------------perl version #!/usr/bin/perl $string = $ARGV[0]; $string =~ /([A-Z]*)([.+-])?([A-Z]?)(#?)/; %seriesmap = ('.' => "Plain", '-' => "Preferred", '+' => "Warrant" ); print "("; print "$1" . ", "; print maybeize($2 , $seriesmap{$2}) . ", "; print maybeize($3 , $3) . ", "; print ((($4 =~ /#/) ? "True" : "False") . ")\n"); sub maybeize ($inp, $out) { my ($inp, $out) = @_; return (($inp eq "") ? "None" : ("Maybe." . $out)); } ----------- python version 1----------------------- #!/usr/bin/python # Using named captures and verbose (ie multiline readable) regexps # Idea being that the regexp captures most of the DSL semantics # ATM the DSL is no pretty (Thats another matter :-) from sys import argv import re seriesmap = {'.':"Plain", '-':"Preferred", '+':"Warrant"} string = argv[1] rexp = r"""(?x) # Verbose re # DSL for describing symbology (?P<scrip> [A-Z]*) # The base scrip (?P<serchar> [.+-])? # Series type char (?P<series> [A-Z])? # Series (?P<issuedc> [#])? # issued char indicator """ rec = re.compile(rexp) m = rec.match(string) if m: g = m.group # DSL -> Python scrip, serchar, series, issuedc = g('scrip'), g('serchar'), g('series'), g('issuedc') # Postprocessing sertype = seriesmap[serchar] issued = issuedc == '#' print "scrip: %s\nsertype: %s\nseries: %s\nissued: %s" % (scrip, sertype, series, issued) else: print "match failed" Finally separating the dsl into a separate file from the python driver: --------- python driver #!/usr/bin/python # Symbology into a separated into file: "symbologydsl.txt" # As of now file name hardwired and needs to be in same directory as this script from sys import argv import re try: # TODO Following needs to be added to dsl file # (?=^.{1,}$) # There better be something >=1 dslfile = "symbologydsl.txt" rexp = open(dslfile, "rU").read() string = argv[1] except IOError as i: if i.errno == 2: # File not found print ("No dsl file") else: print ("IOError: %s" % i.str) exit() except IndexError: print ("No arg given?") exit() seriesmap = {'.':"Plain", '-':"Preferred", '+':"Warrant"} m = re.search(rexp, string, re.VERBOSE) if m: g = m.group # DSL -> Python scrip, serchar, series, issuedc = g('scrip'), g('serchar'), g('series'), g('issuedc') # Postprocessing: series, scrip are left as is sertype = seriesmap[serchar] if serchar else "No Series Type" issued = issuedc == '#' print("scrip:\t%s\ntype:\t%s\nseries:\t%s\nissued:\t%s" % (scrip, sertype, series, issued)) else: print ("match failed") ----------- dsl file: symbologydsl.txt-------- # DSL (instantiation) for describing NYSE symbology ^ (?P<scrip> [A-Z]*) # The base scrip (?P<serchar> [.+-])? # Series type char (?P<series> [A-Z])? # Series (?P<issuedc> [#])? # issued char indicator $ # Thats all (there should be!) ------------------------------------ So now my questions: How do you in perl make regexps readable like python's VERBOSE? Can you do better in perl? -- https://mail.python.org/mailman/listinfo/python-list
