code: def commit_author(sha1=''):
      # type: (str) -> Author
      
      with conf.within_proj_dir():
          cmd = 'git show -s --format="%an||%ae" {}'.format(sha1)
          result = shell.run(
              cmd,
              capture=True,
              never_pretend=True
          ).stdout
          name, email = result.split('||')
          return Author(name, email)
docs: Return the author of the given commit.
  
      Args:
          sha1 (str):
              The sha1 of the commit to query. If not given, it will return the
              sha1 for the current commit.
      Returns:
          Author: A named tuple ``(name, email)`` with the commit author details.