def count(text):
  """
  Count net number of braces in text (add 1 for each opening brace,
  subtract one for each closing brace).

  Parameters
  ----------
  text: String
     A string.

  Returns
  -------
  counts: Integer
     Net number of braces.

  Examples
  --------
  >>> from bibmanager.utils import count
  >>> count('{Hello} world')
  0
  """
  return text.count("{") - text.count("}")