list - Python - ValueError: invalid literal for int() with base 10: '' -

help, keep getting valueerror: invalid literal int() base 10: '' when try extract integer string!

from string import capwords import sys,os import re  def parseint(list):     newlist = [i in list if isinstance(i, int)]     return newlist def getint(string):     number = [int(x) x in string.split("-")]     return number  file=open('./class 1/usr_score.data','r') text=file.read()  def get_num(x):     return int(''.join(ele ele in x if ele.isdigit()))  split = text.split(",")  split.sort(key = lambda k : k.lower()) in split:     print(i)  print ('---------------------------------------') list1=[] in split:     list1.append(str(i))  num_list1=[]  in list1:     ints = re.findall(r'\b\d+\b', i)      #ints = getint(i)[0]     in ints:         int1=i     num_list1.append(i)      #num_list1 = parseint(list1)  num_list=num_list1   in num_list:     print(i) 

the file usr_score.data contains:

user-1,aaa-1,usr-3,aaa-4, 

what code is contains scores game , want program sort them alphabetical order. can please fix problem?

note: of code in program has not been used.

your input data has ',' @ end, causes split() generate empty string in addition scores:

['user-1', 'aaa-1', 'usr-3', 'aaa-4', ''] 

int('') doesn't work; should either remove empty string, or deal it.