Find unique numbers in a file from a line of three number in python

Question

I read a file in python, which contains in each line 2 integer numbers and 1 real. How can i find in python the number of unique number from the 2 first integer number from all the file (except real)?

eg file

1 2 3.3
11 22 33.3
111 222 333.3
11 22 33.3
114 224 334.4

In this example, the result should be 8.

UPDATE this is my code

with open('test.txt','r') as f:
    for line in f:
        for word in line.split():
           print(word)

How can I determine not to consider the real number and after i can do count distinct number from the first two integer in each line

Please show what you have tried and which problems did you encounter. This way you have more chances to get help and less chances to get downvotes — Francesco Montesano, Nov 25 '18 at 09:42
You read in the file line by line, split the line at spaces using `split()` . You convert the resulting strings into numbers, feed them into a set and check how big the set gets. What exactly is your problem? — Patrick Artner, Nov 25 '18 at 09:43
SO is about fixing _your_ Code - not implementing your ideas. Please go over [how to ask](https://stackoverflow.com/help/how-to-ask) and [on-topic](https://stackoverflow.com/help/on-topic) again and if you have questions provide your code as [Minimal, Complete, and Verifiable example](https://stackoverflow.com/help/mcve). — Patrick Artner, Nov 25 '18 at 09:43
This is a question about several things: file reading, filtering, counting. Please show your attempt and which of these things you have trouble with (just one). But I'm quite sure it will turn out to be a question that has been asked before. — trincot, Nov 25 '18 at 09:43
Check: [How to read a file line by line into a list](https://stackoverflow.com/q/3277503/5459839), [How to split a string into a list](https://stackoverflow.com/q/743806/5459839), [How to filter lists](https://stackoverflow.com/q/1596390/5459839), [How do I count unique values inside a list](https://stackoverflow.com/q/12282232/5459839) — trincot, Nov 25 '18 at 09:52

score 1 · Accepted Answer · answered Nov 25 '18 at 09:52

You can use the set function to generate a unique set. For example:

fileName = 'test.txt'
with open(fileName, 'r') as f:
    unique = set()
    for line in f.readlines():
        unique = unique | set(line.split()[:2])
print(unique)

Output:

{'114', '11', '22', '111', '2', '224', '222', '1'}

score 0 · Answer 2 · answered Nov 25 '18 at 10:11

After reading your file, you can get the set of every flattened row slices [:2], then get the length:

from itertools import chain

with open('numbers.txt') as file:
    unique = len(set(chain.from_iterable(x.split()[:2] for x in file)))
    print(unique)

# 8

Find unique numbers in a file from a line of three number in python

2 Answers2