old_contents: from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import subprocess
  import sys
  
  # Attempt to detect https://github.com/docker/compose/issues/4344
  try:
      # We don't try importing pip because it messes with package imports
      # on some Linux distros (Ubuntu, Fedora)
      # https://github.com/docker/compose/issues/4425
      # https://github.com/docker/compose/issues/4481
      # https://github.com/pypa/pip/blob/master/pip/_vendor/__init__.py
      s_cmd = subprocess.Popen(
          ['pip', 'freeze'], stderr=subprocess.PIPE, stdout=subprocess.PIPE
      )
      packages = s_cmd.communicate()[0].splitlines()
      dockerpy_installed = len(
          list(filter(lambda p: p.startswith(b'docker-py=='), packages))
      ) > 0
      if dockerpy_installed:
          from .colors import red
          print(
              red('ERROR:'),
              "Dependency conflict: an older version of the 'docker-py' package "
              "is polluting the namespace. "
              "Run the following command to remedy the issue:\n"
              "pip uninstall docker docker-py; pip install docker",
              file=sys.stderr
          )
          sys.exit(1)
  
  except OSError:
      # pip command is not available, which indicates it's probably the binary
      # distribution of Compose which is not affected
      pass
  
new_contents: from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import subprocess
  import sys
  
  # Attempt to detect https://github.com/docker/compose/issues/4344
  try:
      # We don't try importing pip because it messes with package imports
      # on some Linux distros (Ubuntu, Fedora)
      # https://github.com/docker/compose/issues/4425
      # https://github.com/docker/compose/issues/4481
      # https://github.com/pypa/pip/blob/master/pip/_vendor/__init__.py
      s_cmd = subprocess.Popen(
          ['pip', 'freeze'], stderr=subprocess.PIPE, stdout=subprocess.PIPE
      )
      packages = s_cmd.communicate()[0].splitlines()
      dockerpy_installed = len(
          list(filter(lambda p: p.startswith(b'docker-py=='), packages))
      ) > 0
      if dockerpy_installed:
          from .colors import yellow
          print(
              yellow('WARNING:'),
              "Dependency conflict: an older version of the 'docker-py' package "
              "may be polluting the namespace. "
              "If you're experiencing crashes, run the following command to remedy the issue:\n"
              "pip uninstall docker-py; pip uninstall docker; pip install docker",
              file=sys.stderr
          )
  
  except OSError:
      # pip command is not available, which indicates it's probably the binary
      # distribution of Compose which is not affected
      pass
  
subject: Change docker-py dependency error to a warning, update fix command