Is there a way to read a .txt file and store each line to memory?

Question

I am making a little program that will read and display text from a document. I have got a test file which looks like this:

12,12,12
12,31,12
1,5,3
...

and so on. Now I would like Python to read each line and store it to memory, so when you select to display the data, it will display it in the shell as such:

1. 12,12,12
2. 12,31,12
...

and so on. How can I do this?

Answer 1

I know it is already answered :) To summarize the above:

# It is a good idea to store the filename into a variable.
# The variable can later become a function argument when the
# code is converted to a function body.
filename = 'data.txt'

# Using the newer with construct to close the file automatically.
with open(filename) as f:
    data = f.readlines()

# Or using the older approach and closing the filea explicitly.
# Here the data is re-read again, do not use both ;)
f = open(filename)
data = f.readlines()
f.close()


# The data is of the list type.  The Python list type is actually
# a dynamic array. The lines contain also the \n; hence the .rstrip()
for n, line in enumerate(data, 1):
    print '{:2}.'.format(n), line.rstrip()

print '-----------------'

# You can later iterate through the list for other purpose, for
# example to read them via the csv.reader.
import csv

reader = csv.reader(data)
for row in reader:
    print row

It prints on my console:

 1. 12,12,12
 2. 12,31,12
 3. 1,5,3
-----------------
['12', '12', '12']
['12', '31', '12']
['1', '5', '3']