gs_bucket_validation.py

def IsBucketNameValid(bucket_name):
  """Check if string meets all bucket name requirements.

  Requirements for bucket names defined at:
  https://cloud.google.com/storage/docs/naming

  Args:
    Unicode tring, name of bucket. Full name, including provider prefix, i.e.:
    'gs://my-bucket-name'
  Returns:
    Boolean, whether the bucket name is valid or not.
  """

  def _StripAllowedSymbols(s):
    """Remove '-', '_', '/', and '.' from given string."""
    return ''.join((char for char in s if char not in ['/', '-', '_', '.']))

  if not '://' in bucket_name:
    return False

  prefix, url = bucket_name.split('://')
  url = url.rstrip()
  
  if url[-1] == '/':	
    url = url[:-1]

  return all([
    prefix.isalpha(),
    prefix.islower(),
    len(url) > 2,
    url[0].isalnum(),
    url[-1].isalnum(),
    not url.startswith('goog'),
    not url.isupper(),
    _StripAllowedSymbols(url).isalnum()
  ])