import re


def check_package_name(package_name):
  """Check that package name matches convention

  Args:
    package_name: The package name to validate

  Returns:
    A boolean determining whether the package name is valid or not
  """
  m = re.match('[a-z0-9_]{3,30}', package_name)
  return (m != None and m.group(0) == package_name)