python - Local Variable Reference Before Assignment -

ok i'm making program using tkinter (3.3). user submits name, name searched in database cards.cdb prints out it's information , compares online source url. displays picture of named thing using function picture. when button clicked calls buttonclicked function calls 2 other functions.

from tkinter import * import urllib import urllib.request bs4 import beautifulsoup import pydeck import sys collections import defaultdict  root = tk() name="" def buttonclicked():     name()     picture(text)  def name():     all_lists=[] #all lists     text = inputfield.get()     pydeck.loaddatabase('c://users/trevor/desktop/y-in process/cards.cdb')     cardname = pydeck.getcardsfromname(text)     if not cardname == "":             c = pydeck.card(cardname)     tex.insert(end, c.name)     level="\nlevel %s" % c.level + " " + c.attribute + " " + c.typestring      tex.insert(end, level)     atk="\natk: %s" % c.attack     tex.insert(end, atk)     defe="\ndef: %s" % c.defense     tex.insert(end, defe)     typestring='\n%s' %c.typestring     desc='\n%s' %c.description     seperator='\n--------------------\n'     tex.insert(end, typestring)     tex.insert(end, desc)     tex.insert(end,seperator)     #--     url_name=c.name.replace(' ','_')     url=('http://yugioh.wikia.com/wiki/card_tips:{}'.format(url_name))     page = urllib.request.urlopen(url)     soup = beautifulsoup(page.read())     content = soup.find('div',id='mw-content-text')     links = content.findall('a')     link_lists = defaultdict(list)     all_lists.append([link.get("title") link in links])     common_links = set(all_lists[0]).intersection(*all_lists[1:])     omit_list=['none', 'special summon', 'edit searchable section', 'edit special summoned hand section','edit special summoned deck section','edit special summoned graveyard section','edit easier tribute summons section','edit generic tips section','edit traditional format section']     final=set(common_links)-set(omit_list)     tex.insert(end,final)     #--     tex.see(end)             # scroll if necessary   def picture(text):     gifdir = "c:\\users\\trevor\\desktop\\y-in process\\pictures\\"     pydeck.loaddatabase('c://users/trevor/desktop/y-in process/cards.cdb')     cardname = pydeck.getcardsfromname(text)     if not cardname == "":         c=pydeck.card(cardname)     filename='{}.gif' .format(c.cardid)     img = photoimage(file=gifdir+filename)     can = canvas(root)     can.pack(fill=both,side='left')     can.config(width=img.width(), height=img.height())             can.create_image(2, 2, image=img, anchor=nw)  tex=text(root) tex.pack(side='right') inputfield = entry(root) inputfield.pack(side='bottom') = button(root,text="enter name", command = buttonclicked) #calls name function but.pack(side='bottom') text = inputfield.get()   root.mainloop() 

i'm getting error

filename='{}.gif' .format(c.cardid) unboundlocalerror: local variable 'c' referenced before assignment 

i know means c isn't being created in picture function define doesn't recognize it.

anybody have suggestions cause i'm stumped?

if not cardname == "":     c=pydeck.card(cardname) filename='{}.gif' .format(c.cardid) 

and happens if cardname is equal "" ?

since place c initialized, if cardname empty you'll see error. need define should happen cardname empty, , handle condition accordingly.