Program in python 3: This is my first program involving files. I need to ignore comment lines (start with #) and blank lines, and then split the lines so they are iterable, but I keep on getting and IndexError message that says string index out of range, and the program crashes on the blank line.
import os.path
def main():
endofprogram = False
try:
#ask user to enter filenames for input file (which would
#be animals.txt) and output file (any name entered by user)
inputfile = input("Enter name of input file: ")
ifile = open(inputfile, "r", encoding="utf-8")
#If there is not exception, start reading the input file
except IOError:
print("Error opening file - End of program")
endofprogram = True
else:
try:
#if the filename of output file exists then ask user to
#enter filename again. Keep asking until the user enters
#a name that does not exist in the directory
outputfile = input("Enter name of output file: ")
while os.path.isfile(outputfile):
if True:
outputfile = input("File Exists. Enter name again: ")
ofile = open(outputfile, "w")
#Open input and output files. If exception occurs in opening files in
#read or write mode then catch and report exception and
#exit the program
except IOError:
print("Error opening file - End of program")
endofprogram = True
if endofprogram == False:
for line in ifile:
#Process the file and write the result to display and to the output file
line = line.strip()
if line[0] != "#" and line != None:
data = line.split(",")
print(data)
ifile.close()
ofile.close()
main() # Call the main to execute the solution
Your problem comes from the fact that empty lines are not None, as you seem to assume. The following is a possible fix:
for line in ifile:
line = line.strip()
if not line: # line is blank
continue
if line.startswith("#"): # comment line
continue
data = line.split(',')
# do stuff with data