如何从文本文件中挑选出整数和字符串？

Question

So I'm trying to create a program wich reads a text file and outputs the strings and integers in some sortations.

I'd like to print out at which row the strings were at and also create lists with all the integers in the text file. (To further use the integers to find min, max, median etc)

Ive tried and got stuck completely unfortunally.

def readfile(file):
    try:
        f = open(file, 'r')
        fil = f.readlines()
        f.close()
        return fil
    except IOError:
        print('fil finns inte')
        return None

def rader(rowlist):
    k=rowlist
    l=[]
    try:
        for i in k:
            l.append(int(i.strip()))
            return l
    except:
        print("sds")

So this code is obviosuly not finished and also is currently run with a doctest. Im stuck at the part where i want to sort the integers to a list and the strings to print out togeather with the row number.

So obviosuly I'd like a loop which goes through a list of the document, when it hits an integer, append it to a list and when it hits an string, stop, just to the except case or something like that, and print the string out togeather with the number of the row (i).

How do i create this? I'm not looking for a very complicated program, but more a simple loop which I just cant see in my head how to code.

Your's truely, a distressed student.

Answer 1

Please see an example:

def get_integer_or_none(text):
    '''
    Returns integer from text or None if text is not an integer.
    '''
    try:
        return int(text)
    except ValueError:
        return None

for text in ('1', 'some text', '2 not an integer', '-1000'):
    integer_value = get_integer_or_none(text)
    if integer_value is not None:
        print('This text "{}" is an integer ({})'.format(text, integer_value))
    else:
        print('This text "{}" is not an integer'.format(text))