old_contents: """Code eval Fizz Buzz"""
  import sys
  
  
  def main(filename):
      """Open file and perform fizz_buzz on each line."""
      with open(filename, 'r') as file_handle:
          for line in file_handle:
              fizz_buzz(line)
  
  
  def divisible(num, denom):
      """Return true if num is divisible by denom, false otherwise."""
      if num % denom == 0:
          return True
      else:
          return False
  
  
  def fizz_buzz(line):
      """Print correct fizz buzz output given input line."""
      inp = line.split(' ')
      x, y, num = int(inp[0]), int(inp[1]), int(inp[2])
      output = []
      for num in xrange(1, num+1):
          out = ''
          if divisible(num, x):
              out = 'F'
          if divisible(num, y):
              out = '{}B'.format(out)
          if not out:
              output.append(str(num))
          else:
              output.append(out)
      print ' '.join(output)
  
  
  if __name__ == '__main__':
      filename = sys.argv[1]
      main(filename)
  
new_contents: """Code eval Fizz Buzz"""
  import sys
  
  
  def main(filename):
      """Open file and perform fizz_buzz on each line."""
      with open(filename, 'r') as file_handle:
          for line in file_handle:
              fizz_buzz(line)
  
  
  def divisible(num, denom):
      """Return true if num is divisible by denom, false otherwise."""
      if num % denom == 0:
          return True
      else:
          return False
  
  
  def fizz_buzz(line):
      """Print correct fizz buzz output given input line."""
      inp = line.split(' ')
      x, y, num = int(inp[0]), int(inp[1]), int(inp[2])
      output = []
      for num in xrange(1, num+1):
          if divisible(num, x) and divisible(num, y):
              output.append('FB')
          elif divisible(num, x):
              output.append('F')
          elif divisible(num, y):
              output.append('B')
          else:
              output.append(str(num))
      print ' '.join(output)
  
  
  if __name__ == '__main__':
      filename = sys.argv[1]
      main(filename)
  
subject: make more pythonic.