Creating a number array out of a text file on python

Question

I want to create an array of numbers out of every line of a text file, The file contains numbers as follow:

This is the code i have to open the file and append the numbers to the array:

f = open('randomNumberx.txt','r')
myList = []
for line in f:
    myList.append(line.strip())

the code above gives me the following:

['11', '9', '7', '12' ]

and id like to have it as:

[11,9,7, 12]

i am using this for a sorting algorithm and when i have the numbers with the '' it makes my algorithm fail and if i use the array of numbers it works fine. any ideas?

Strings are compared lexicographically, so '2'> '100' is True, that's why sort returns unexpected output. — Ashwini Chaudhary
– Ashwini Chaudhary, Commented Feb 10, 2014 at 8:01

msvalkon · Accepted Answer · 2014-02-10 08:13:05Z

2

Try this:

with open('randomNumberx.txt','r') as f:
    mylist = [int(x) for x in f]

You can also use mylist = map(int, f) as commented by @falsetru.

You should learn to use the with -statement. It's useful for many situations in python. For files, it handles the opening and closing of the file so you won't have to.

Read this and this.

edited Feb 10, 2014 at 8:13

answered Feb 10, 2014 at 8:01

msvalkon

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4 Comments

falsetru Over a year ago

Itearting a file object yields lines. readlines() is not necessary. It will load all lines at once.

Ashwini Chaudhary Over a year ago

I didn't downvote, but you don't need the strip call and no need to use f.readlines(), simply iterate over the file object.

falsetru Over a year ago

strip() is not required. int() ignore spaces.

user3291939 Over a year ago

Pretty neat, this did it!

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