title: how to skip over lines of a file if they are empty
body: <p>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. </p>
  
  <pre><code>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
  </code></pre>