#!/kunden/homepages/9/d92057734/htdocs/.htapps/bin/python import cgi import cgitb cgitb.enable() import re from polynomial2 import sanitize,tokenize,shunting_yard,eval_rpn,eval_exp def step_by_step(expression): clean = sanitize(expression) yield clean tokens = tokenize(clean) yield tokens rpn = shunting_yard(tokens) yield rpn yield eval_rpn(rpn) def superscript(text): return re.sub(r'\^([0-9]+|[0-9]\+.[0-9]+)',r'\1',text) def format(_list): s = str(_list) for char in '"\'[],': s = s.replace(char,'') return cgi.escape(s) form = cgi.FieldStorage() expression = form.getfirst('expression') expand = form.getfirst('expanded') == 'True' print "Content-Type: text/html\n" style = """\ """ print "Polynomial Evaluation%s" % style print "The polynomial evaluator is totally unreliable, and thus should not be used for situations such as math homework
" if expression: if 'answertolifetheuniverseandeverything' in expression.replace(' ','').replace(',','').lower(): expression = '24' text = superscript(cgi.escape(str(expression))) print '
Evaluation of "%s"' % text ## try: if expand: print """Sanitized form:
  %s

Tokenized form:
  %s

RPN form:
  %s

Final evaluation:
  %s
""" % tuple([format(step) for step in step_by_step(expression)]) else: print """
  %s
""" % superscript(str(eval_exp(expression))) ## except: ## print "
  ERROR while evaluating

" print '
' print """
Polynomial Evaluation Exponentiation is denoted by ^ (ie a^2 for a2) and a^2b^2 = a2b2,not a2b2.
Expanded display
""" % ((expand and [' checked'] or [''])[0])