import sys

# Description: Loads a file into a list of lines
#
# Parameters: parameter 1 is the name of the file that I want to load
#
# Return: A list containing elements which are each single line from the file
def loadLines(filename):

	# Open the file with the name Filename.  If this file doesn't exist
	# the except statement in my main() function will catch it
	aFile = open(filename)

	# Create a new list where I will add the lines from the file 
	lines = []

	# Grab a single line from the file
	line = aFile.readline()

	# While the line is not blank (blank signifies the end of the file)
	while line != '':
		# Add this line to my list, removing the new line character at the end
		lines.append(line.rstrip())
		# Grab the next line from the file
		line = aFile.readline()

	# Once I finished reading, close the file
	aFile.close()

	# Return the list of lines in the file
	return lines


# This is the very high level of my program that will run all of the smaller pieces of my program
def main():
	try:
		filename = sys.argv[1] # Try to take the argument from the command line
		lines = loadLines(filename) # Load the file into a list of lines
		print lines # Print the lines to screen
	
	# If the argument from the command line is not there, inform the user of proper 
	# Syntax for running my program
	except IndexError: 
		sys.stderr.write("Please provide a filename.  Proper format 'python try-except.py [filename]'\n")
	# If the specified file doesn't exist, inform the user
	except IOError:
		sys.stderr.write("The specified File does not exist\n")
main()