Taking the average of integers in a text file (using Python)

Question

This is my code:

results = [[usernme, score]]

with open("hisEasyR.txt", "a") as hisEasyRFile:
        writer = csv.writer(hisEasyRFile, delimiter='|')
        writer.writerows(results)

This is what the text file looks like:

mary|4
john|5
ben|3

I want to take all the integers and calculate the average. For example, for this file, I would want it to output:

The average is 4.

How would I go about doing this?

srikavineehari · Accepted Answer · 2018-01-21T19:26:26.647

1

You could use list comprehension:

with open("hisEasyR.txt") as hisEasyRFile:
    numbers = [int(line.rstrip('\n').split('|')[-1])
               for line in hisEasyRFile if not line.isspace()]

print "The average is %d." % (sum(numbers) / len(numbers))
# The average is 4.

edited Jan 21 '18 at 19:26

answered Jan 21 '18 at 16:34

srikavineehari

2,502
1
11
21

Hiya, sorry, I'm definietly not an expert in Python. I'm so bad at trying to correct prrograms haha. I'm getting the error `print "The average is %d." % (sum(ls) / len(ls)) NameError: global name 'ls' is not defined` – Programmer12 Jan 21 '18 at 19:08
@Programmer12, sorry it was a typo. Changed it to `numbers`. Now it should work. – srikavineehari Jan 21 '18 at 19:27
Perfect!! Thanks! How do I go about changing the average to a float if I wanted to? I tried to change the 'int' in `numbers = [int(line.rstrip('\n').split('|')[-1])` to `float` but it didn't have any affect :) – Programmer12 Jan 21 '18 at 21:00
Change `int(line.rstrip('\n').split('|')[-1])` to `float(line.rstrip('\n').split('|')[-1])`. – srikavineehari Jan 21 '18 at 21:05
And in the `print` statement, change `%d` to `%f`. – srikavineehari Jan 21 '18 at 21:10
If you want to truncate it to, say, two decimal places, you could do so with `%.2f` – srikavineehari Jan 21 '18 at 21:14
Ah I see. Amazing! Thanks so much. – Programmer12 Jan 21 '18 at 21:56

score 0 · Answer 2 · answered Jan 21 '18 at 15:52

The long way: Read line by line, use string split on the |. Then take the second string, (which is the number), and cast it to an int.

Refer to: https://www.tutorialspoint.com/python/string_split.htm

Pseudo:

sum = 0

For line in file:
     mySplit = str.split(line, '|')
     sum += int(mySplit[1])

avg = sum/numLines

Aviad Levy · Answer 3 · 2018-01-21T20:59:55.910

0

In two lines: (assuming you already read the entire file to content)

new_list = [int(i.split("|")[1]) for i in content.split("\n") if "|" in i]
print "The average is " + str(sum(new_list) / float(len(new_list)))

edited Jan 21 '18 at 20:59

answered Jan 21 '18 at 16:03

Aviad Levy

750
4
13

I'm fairly new to Python haha. Could you give me an example of how to read the file to content? – Programmer12 Jan 21 '18 at 19:14
In short: `with open('Path/to/file', 'r') as file: content = file.read()` take a look here: https://stackoverflow.com/questions/7409780/reading-entire-file-in-python – Aviad Levy Jan 21 '18 at 19:27
Thanks! I'm getting the error `IndexError: list index out of range` – Programmer12 Jan 21 '18 at 19:30
`new_list = [int(i.split("|")[1]) for i in content.split("\n")] IndexError: list index out of range` – Programmer12 Jan 21 '18 at 20:52
what's your input? I guess the problem is with empty lines. I updated my answer – Aviad Levy Jan 21 '18 at 20:57

Taking the average of integers in a text file (using Python)

3 Answers3