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

Question

Help, I keep getting ValueError: invalid literal for int() with base 10: '' when I try to extract an integer from a string!

from string import capwords
import sys,os
import re

def parseint(List):
    newlist = [i for i in List if isinstance(i, int)]
    return newlist
def getint(string):
    number = [int(x) for 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 for ele in x if ele.isdigit()))

split = text.split(",")

split.sort(key = lambda k : k.lower())
for i in split:
    print(i)

print ('---------------------------------------')
list1=[]
for i in split:
    list1.append(str(i))

num_list1=[]

for i in list1:
    ints = re.findall(r'\b\d+\b', i)

    #ints = getint(i)[0]
    for i in ints:
        int1=i
    num_list1.append(i)

    #num_list1 = parseint(list1)

num_list=num_list1


for i in num_list:
    print(i)

The file usr_score.data contains:

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

What my code is is that it contains scores for a game and I want my program to sort them into alphabetical order. Can someone please fix my problem?

Note: Some of the code in the program has not been used.

Answer 1

int() can't take an empty string, that's an invalid parameter for it. You'll need to test for if a string is empty when getting it as an int. You can do that in a list comprehension like this:

[int(x) if not (x.isspace() or x == '') else 0 for x in string.split("-")]

You can replace 0 with None or some other result if you'd prefer, but this basically always checks that a string isn't just whitespace characters using the string.isspace() function and also makes sure x isn't an empty string.

Answer 2

Your input data has a ',' at the end, which causes split() to generate an empty string in addition to the scores:

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

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