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1

I have to list a integers from a text file separated by newlines into a python list. I ended up with the code above which works (for my case) but certainly is far form optimal.

def readIntegers(pathToFile):

    f = open(pathToFile)
    contents = f.read()
    f.close()

    tmpStr = ""

    integers = []

    for char in contents:

        if char == '\r':
            integers.append(int(tmpStr))
            tmpStr = ""
            continue

        if char == '\n':
            continue

        tmpStr += char

    return integers

Now I have much less code, but I'm not sure for which cases split() works correctly.

def readIntegers(pathToFile):

    with open(pathToFile) as f:
        a = [int(x) for x in f.read().split()]
    return a
share|improve this question

1 Answer 1

up vote 11 down vote accepted

No need for split (you can use readlines). But no need for readlines, for that matter:

def read_integers(filename):
    with open(filename) as f:
        return map(int, f)

or, if that’s more to your fancy:

def read_integers(filename):
    with open(filename) as f:
        return [int(x) for x in f]

A file object is simply iterable in Python, and iterates over its lines.

Note that, contrary to what I said earlier, wrapping the file object in a with block is highly recommended. Python doesn’t actually guarantee (although it recommends it) that objects are disposed of automatically at the end of the scope. Worse, it’s not guaranteed that a file object that is collected actually closes the underlying stream.

(Note that I’ve adapted the method name to Python conventions.)

share|improve this answer
    
Thx for your answer :) I didn't think of using map here. –  Nils Jun 11 '12 at 6:02

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