python post and get commands -

i have been having trouble post function. application design people enter birthday , if put in month, day, , year in right post "thanks! that's totally valid day" if not date post "that doesn't valid me, friend", not refreshes self each time push submit. in code did go wrong post function or , post function?

import webapp2  form="""   <form method="post">     birthday?     <br>     <label>month<input type="type" name="month"></label>     <label>day<input type="type" name="day"></label>     <label>year<input type="type" name="year"></label>     <div style="color: red">%(error)s</div>     <br>     <br>     <input type="submit"> </form>  """  class mainpage(webapp2.requesthandler):      def write_form(self, error=""):         self.response.out.write(form % {"error": error})      def get(self):         self.write_form()      def valid_year(year):         if year , year.isdigit():             year = int(year)             if year > 1900 , year < 2020:                 return year      def valid_day(day):         if day , day.isdigit():             day = int(day)             if day > 0 , day <= 31:                 return day      months = ['janurary',           'february',           'march',           'april',           'may',           'june',           'july',           'august',           'september',           'october',           'november',           'december']       month_abbvs = dict((m[:3].lower(),m) m in months)      def valid_month(month):         if month:             short_month =  month[:3].lower()             return month_abbvs.get(short_month)         def post(self):         user_month = valid_month(self.request.get('month'))         user_day = valid_day(self.request.get('day'))         user_year = valid_year(self.request.get('year'))         if not (user_month , user_day , user_year):             self.write_form("that doesn't valid me, friend.")         else:             self.response.out.write("thanks! that's totally valid day!")  app = webapp2.wsgiapplication([('/',mainpage)], debug=true) 

i download python idle , use instead of notpad++. when push submit got:

 internal server error  server has either erred or incapable of performing requested operation.  traceback (most recent call last):   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1535, in __call__     rv = self.handle_exception(request, response, e)   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1529, in __call__     rv = self.router.dispatch(request, response)   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1278, in default_dispatcher     return route.handler_adapter(request, response)   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 1102, in __call__     return handler.dispatch()   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 572, in dispatch     return self.handle_exception(e, self.app.debug)   file "c:\program files (x86)\google\google_appengine\lib\webapp2-2.5.2\webapp2.py", line 570, in dispatch     return method(*args, **kwargs)   file "c:\users\ajper_000\desktop\engineapp\main.py", line 66, in post     user_month = valid_month(self.request.get('month')) nameerror: global name 'valid_month' not defined 

try replace

<form> 

with

<form method="post"> 

forms, default, use requests, while request handler expects post request.

edit: appears have multiple problems:

1. the original problem, above anwser.
2. your indentation wrong, causing post method undefined (or defined within get method maybe)
3. the valid_* methods undefined - need define them.