old_contents: import subprocess
  import os
  
  class PHPLint:
      def __init__(self):
          self.silent = False
  
      def setSilentLint(self, isSilent):
          self.silent = isSilent
  
      def lint(self, path):
          if os.path.isfile(path):
              self.lintFile(path)
          elif os.path.isdir(path):
              self.lintDir(path)
  
      def lintFile(self, path):
          if self.isPHPFile(path):
              process = subprocess.Popen(['php', '-l', path], shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
              (processStdOut, processStdErr) = process.communicate();
              if not self.isSilentLint():
                  print processStdOut.rstrip()
              if process.returncode > 0:
                  print processStdErr.rstrip()
                  raise SystemExit(1)
  
      def lintDir(self, path):
          for rootDir, dirName, files in os.walk(path):
              for f in files:
                  self.lintFile(os.path.join(rootDir, f))
  
      def isPHPFile(self, filename):
          return filename.endswith('.php')
  
      def isSilentLint(self):
          return self.silent
  
  
new_contents: import subprocess
  import os
  
  class PHPLint:
      def __init__(self):
          self.silent = False
  
      def set_silent_lint(self, is_silent):
          self.silent = is_silent
  
      def lint(self, path):
          if os.path.isfile(path):
              self.lint_file(path)
          elif os.path.isdir(path):
              self.lint_dir(path)
  
      def lint_file(self, path):
          if self.is_php_file(path):
              process = subprocess.Popen(['php', '-l', path], shell=False,
                                          stdout=subprocess.PIPE, stderr=subprocess.PIPE)
              (process_stdout, process_stderr) = process.communicate();
              if not self.is_silent_lint():
                  print process_stdout.rstrip()
              if process.returncode > 0:
                  print process_stderr.rstrip()
                  raise SystemExit(1)
  
      def lint_dir(self, path):
          for root_dir, dir_name, files in os.walk(path):
              for f in files:
                  self.lint_file(os.path.join(root_dir, f))
  
      def is_php_file(self, filename):
          return filename.endswith('.php')
  
      def is_silent_lint(self):
          return self.silent
  
  
subject: Change code to be compliant with PEP 8