Python error in shell ValueError: invalid literal for int() with base 10:

Question

I am writing a program. if short matches are mixed with longer matches. the program is to see which matches will fit back in the short box. This is my code:

import math
def q2():

    fin = open('input.txt','rt')
    fout = open('output.txt', 'wt')
    a= int(fin.readline().strip())
    b = [int(b) for b in str(a)]
    count = -1
    nMatches = b[0]
    width = b[1]
    heigth = b[2]
    length = width**2 + heigth**2
    length = length**(.5)
    while count <= nMatches:
        match = int(fin.readline().strip())
        count = count+ 1
        if match <= length:
            print('YES')
        else:
            print('NO')

This is the output:

YES
YES
YES
NO
NO
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    q2()
  File "D:/code/Q2/q2.py", line 15, in q2
    match = int(fin.readline().strip())
ValueError: invalid literal for int() with base 10: ''

Thanks for any help the content of fin is: 534 3 4 5 6 7

Can you just print `match` and see what value you are getting ? — Tanveer Alam, Jan 12 '15 at 20:54
Maybe I'm wrong, but does the exception not just show that he's trying to convert an empty string '' into an int? 10seconds for finding 4 sites to a solution to this problem. — ProgrammingIsAwsome, Jan 12 '15 at 21:03

score 0 · Answer 1 · edited May 23 '17 at 11:57

0

It looks like you want to convert an empty string to an int. But that's not possible. Look at your exception: ... base 10: '' <-- this is an empty string.

So you read a line, you strip it and then just an empty string is left. And that raises the ValueError

Here a stackoverflow answer (1 oder 2 result on google): ValueError: invalid literal for int() with base 10: ''

edited May 23 '17 at 11:57

Community

1
1

answered Jan 12 '15 at 20:58

ProgrammingIsAwsome

1,109
7
15

score 0 · Answer 2 · answered Jan 12 '15 at 21:01

0

The problem is your loop count. Instead of using while count < nMatches why not just for i in range(nMatches)? Because your loop count is off, you're reading past the end of the file, which gives an error when you try to convert the empty string.

answered Jan 12 '15 at 21:01

Mark Ransom

299,747
42
398
622

score 0 · Answer 3 · answered Jan 12 '15 at 21:30

I am making a lot of assumptions here because I don't know what is in the fin file. This is what I think you are trying to do: nMatches = 534 is the number of matches in the box. width = 3 and height = 4 and somehow the that causes the length of the box to be 5

I am assuming that all the numbers after the first 3 in the fin file are the length of each match.

    from math import sqrt
    def q2():

    fin = open('text.txt','r')
    fout = open('output.txt', 'w')
    a = fin.readline().strip().split()
    b = [int(x) for x in a]
    nMatches = b[0]
    width = b[1]
    height = b[2]
    length = sqrt(width**2 + height**2)

    for match in b[3:]:

        if match <= length:
            print ('YES')
        else:
            print ('NO')

    q2()

This compares each number in the file to the length of the box.

Python error in shell ValueError: invalid literal for int() with base 10:

3 Answers3