Backslashes in container command requires double escaping

Passing the \ character to the daemon in the containers.create method command argument requires escaping twice, once for the string in Python, and then again for something that requires it internally. From a user perspective, given that the command can be given as a string, I'd expect this string to match one that would be provided to the docker CLI:

  $ docker run --rm alpine:3.10 echo char: \
  char: \

With the following:

  import docker

  cli = docker.from_env()
  print(cli.containers.run('alpine:3.10', command='echo char: \\').decode('utf-8'))

• Expected output: char: \
• Actual output: ValueError: No escaped character
• Required command for expected output: 'echo char: \\\\', r'echo char: \\'

I should also note that I first encountered this passing an msbuild command to a Windows container where providing the %5C escape code also seemed to work but not for the alpine container, guessing this was handled by something else.

Start with the containers.create and containers.run command arguments and reproduce the issue using the Python snippet and alpine:3.10. Trace how a string command is processed before reaching the daemon, then verify that a single backslash produces the expected char: \ output without requiring double escaping.