CODEWITHSUNDEEP
python
Anurag Ramdasan
Anurag Ramdasan

Reputation: 4330

Python - reading from file into a list

This is simple but I just cant seem to get it right.

I have a text file containing numbers in the form 

0 1 2
3 43 
5 6 7 8

and such.

I want to read these numbers and store it in a list such that each number is an element of a list. If i read the entire file as a string, how can I split the string to get these elements separated?

Thanks.

Upvotes: 1

Views: 158

Answers (3)

ApproachingDarknessFish
ApproachingDarknessFish

Reputation: 14313

First, open the file. Then iterate over the file object to get each of its lines and call split() on the the line to get a list of strings. Then convert each string in the list to a number:

f = open("somefile.txt")

nums = []
strs = []

for line in f:
    strs = line.split() #get an array of whitespace-separated substrings 
    for num in strs:
         try:
             nums.append(int(num)) #convert each substring to a number and append
         except ValueError: #the string cannot be parsed to a number
             pass

nums now contains all of the numbers in the file.

Upvotes: 1

Blender
Blender

Reputation: 298046

You can iterate over the file object as if it were a list of lines:

with open('file.txt', 'r') as handle:
    numbers = [map(int, line.split()) for line in handle]

A slightly simpler example:

with open('file.txt', 'r') as handle:
    for line in handle:
        print line

Upvotes: 3

Brendan Long
Brendan Long

Reputation: 54232

how can I split the string to get these elements separated

string.split()

Upvotes: 0

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