Identifying integers from a list with strings and integers

Question

I am storing data from a file into a list to analyse it for patterns. My intention is to be able to read a txt or csv file. I am struggling to find a way to analyse the information from the original list that is stored from the file to identify integers within that list.

I have tried the .isdigit() builtin method but that is returning False although the 'data' list is numbers, comma's and a some string's. The 'data' list does not have string numbers just integers.

It works as expected until the noCheck function, which just prints the ValueError.

data = []
IntData = []

def analyse():
    try:
        openfile = input('Enter file path: ')
        with open(openfile) as f:
            read = f.read()
            data.append(read)
            print(data)
            next = input('Press any Key to continue..')
            if next == '':
                noCheck()
    except FileNotFoundError:
        print('No File Found')

def noCheck():
    for number in data:
        try:
            IntData.append(int(number))
            print(IntData)
        except ValueError:
            print('No numbers found')


analyse()

Any help is greatly appreciated

EDIT: This is the data in the txt file:

08,30,34,44,45,57\n09,18,20,42,43,46\n14,19,30,45,48,58\n02,04,17,28,37,45\n14,18,23,28,36,37\n05,08,40,41,43,45\n18,25,29,32,35,58\n04,10,11,17,53,54\n24,30,44,50,56,57

Maybe you should put each line of the file into a separate element of `data`? You're putting the entire file into a single element. — Barmar, Aug 05 '19 at 19:54
And if it's a CSV file, you need to split each line at comma characters. Maybe use the `csv` module. — Barmar, Aug 05 '19 at 19:56
Yes I know, I want to parse the numbers from the all other characters in the list. My idea was passing the data through int function to drop all other characters from the list and store it in a new list so it can be passed through a function later on — Barb, Aug 05 '19 at 20:32

score 0 · Accepted Answer · answered Aug 05 '19 at 19:56

0

Your question is asking to identify if there are any integers in the lines being read. Your code is currently just casting the lines to integers, instead of checking if they are integers.

I don't know how your file looks like, but you can do:

for line in data:
    if(isinstance(line, int)):
        IntData.append(line)

You also want to check the contents of IntData at the very end of reading your file, instead of throwing an exception after each line.

You can simply add:

if (len(IntData) == 0):
    print("No integers")
else:
    print("There are integers")

answered Aug 05 '19 at 19:56

alex067

3,159
1
11
17

This won't work. `f.read()` returns a string, `isInstance(line, int)` will never be true. – Barmar Aug 05 '19 at 19:57
His code is casting the lines to integers, and if it gets an error he knows it's not an integer. It's the right general idea. – Barmar Aug 05 '19 at 19:58
doesn't python cast chars to ascii characters though? – alex067 Aug 05 '19 at 19:58
No, it doesn't, you have to call `int()` explicitly. – Barmar Aug 05 '19 at 20:01

Jainil Patel · Answer 2 · 2019-08-05T23:12:55.473

data = []
IntData = []

def analyse():
    try:
        openfile="ex1data1.txt"
        with open(openfile) as f:
            read = f.read()
            data.append(read)
            print(data)
            next = input('Press any Key to continue..')
            if next == '':
                noCheck()
    except FileNotFoundError:
        print('No File Found')

def noCheck():
    for number in data:
        num=number.replace('\\n',',')
        numlist=num.split(',')
        for i in numlist:
            try:
                IntData.append(int(i))
                print(IntData)
            except ValueError:
                print('No numbers found')


analyse()

instead of giving int('2,3,4,\n') you have to give int(2)...

so use

print (re.findall("\d+", s))

data = []
IntData = []
import re


def analyse():
    try:
        openfile="ex1data1.txt"
        with open(openfile) as f:
            read = f.read()
            data.append(read)
            print(data)
            next = input('Press any Key to continue..')
            if next == '':
                noCheck()
    except FileNotFoundError:
        print('No File Found')

def noCheck():
    for i in data:
        for k in re.findall("\d+", i):
            IntData.append(k)


analyse()

for further information :Extract Number from String in Python

It is a solution to an example of knowing what the file contains, I would have to rewrite the code dependable upon the file that I am reading in case of instances that contain other characters other than \n or a comma. num.replace() only takes 3 arguments at most. I cannot pass a module through it only string so if the text contained anymore than 3 strings it would not parse to just integers — Barb, Aug 05 '19 at 21:24

Identifying integers from a list with strings and integers

2 Answers2