docs: def get_username():
  	"""
  	Try to retrieve the username from a variety of sources.  First the
  	environment variable LOGNAME is tried, if that is not set the
  	environment variable USERNAME is tried, if that is not set the
  	password database is consulted (only on Unix systems, if the import
  	of the pwd module succeeds), finally if that fails KeyError is
  	raised.
  	"""
  	try:
  		return os.environ["LOGNAME"]
  	except KeyError:
  		pass
  	try:
  		return os.environ["USERNAME"]
  	except KeyError:
  		pass
  	try:
  		import pwd
  		return pwd.getpwuid(os.getuid())[0]
  	except (ImportError, KeyError):
  		raise KeyError