Appending Lines from a File into a List

Question

I am trying to write a function that reads a file, and appends the lines of a file into a list. For example a file that reads:

hello
goodbye 

should return the list:

[["h","e","l","l","o"]
 ["g","o","o","d","b","y","e"]]

I have created a helper function splitLine that takes as input, a string and would return a list of the letters in the string. For example "abc" would become ["a","b","c"]

I am having trouble inserting new lines and stripping the "\\r" and "\\n" from the lists. Here is my code:

def createGrid(filename):
    myFile = open(str(filename),"r")
    myGrid = []
    for line in myFile:
        myLine = splitLine(line)
        myGrid.append(myLine)
    return myGrid

Answer 1

You can probably try iterate through multiple for loops like this

def createGrid(filename):
    myFile = open(str(filename),"r")
    myGrid = []
    for line in myFile:
        for apl in line:
            myLine = apl.splitlines()
            myGrid.append(myLine)
    return myGrid

Answer 2

A lot of what you want to do is handled by built-in methods in Python.

Wrapping list() around a string will split it into a list of characters; using the .strip() method on a string will remove leading and trailing whitespaces (such as '\\r\\n' ); and you can loop through each row of a file you have opened using a for loop.

def create_grid(filename):
    with open(filename, 'r') as fp:
        return [list(row.strip()) for row in fp]

Answer 3

Here is another solution:

def createGrid(filename):
    myFile = open(str(filename),"r")
    myGrid = []
    for line in myFile:
        myGrid.append(list(line.strip()))
    return myGrid

print createGrid("input.txt")

output:

[['h', 'e', 'l', 'l', 'o'], ['g', 'o', 'o', 'd', 'b', 'y', 'e']]