How to define key in this code python -

i want code record latest 3 scores each student , when 4th 1 added overwrite oldest score , replace new one. need layout be:

f,7,8,9 

i have created code when run it asks me define key. code:

pname = input("what name") correct = input("what score") score_filename  = "class1.txt" max_scores = 3  try: scoresfile = open('class1.txt', "r+") except ioerror: scoresfile = open('class1.txt', "w+") # file not exists  actualscorestable = dict()  line in scoresfile:     tmp = line.replace("\n","").split(",")     actualscorestable[tmp[0]]=tmp[1:] scoresfile.close()   if pname not in actualscorestable.keys():     actualscorestable[pname] = [correct] else:     actualscorestable[pname].append(correct)     if max_scores < len(actualscorestable[pname]):             actualscorestable[key].pop(0)   scoresfile = open(score_filename, "w+") # truncating file (write again) key in actualscorestable.keys():     scoresfile.write("%s,%s\n" % (key, ','.join(actualscorestable[key]))) scoresfile.close() 

when run code tells me 'key' not defined. how define key? have been told needs tuple dont know how make , code work.

traceback (most recent call last):   file "c:\users\milan\documents\python\task 3 tries\3 scores.py", line 23, in <module>     actualscorestable[key].pop(0) nameerror: name 'key' not defined 

the error in line:

actualscorestable[key].pop(0)

you don't define key until after code. think want actualscorestable[pname].pop(0).