Putting a matrix from a text file into a list

Question

I'm trying to read a text file with matrix and put it in a list, but I am using two loops here and I want my function to be faster.

def read_file(path_to_file):
 mylist=[]
 for eachLine in open(path_to_file,'rt'):
 mylist.append([int(eachRow) for eachRow in eachLine.split()])
 return mylist

• hpaulj: Since the result will be a list of lists and int can handle only one number at a time, you have to have 2 loops of some sort.

Answer 1

Not sure if it's possible to make this faster. But it can be better:

with open(path_to_file, 'rt') as fh:
 return [[int(value) for value in line.split()] for line in fh]

First of all, you should always use a with ... context manager when working with files. That way you cannot forget to close the file handle after you are done reading from it.

Other improvements:

• More natural variable names
• Simpler and more compact writing style using a list comprehension

Also keep in mind PEP8, the Python style guide.