code: def bool_env(key, default=False):
      
      try:
          return os.environ[key].lower() in TRUE
      except KeyError:
          return default
docs: Parse an environment variable as a boolean switch
  
      `True` is returned if the variable value matches one of the following:
  
      - ``'1'``
      - ``'y'``
      - ``'yes'``
      - ``'true'``
  
      The match is case-insensitive (so ``'Yes'`` will match as `True`)
  
      Parameters
      ----------
      key : `str`
          the name of the environment variable to find
  
      default : `bool`
          the default return value if the key is not found
  
      Returns
      -------
      True
          if the environment variable matches as 'yes' or similar
      False
          otherwise
  
      Examples
      --------
      >>> import os
      >>> from gwpy.utils.env import bool_env
      >>> os.environ['GWPY_VALUE'] = 'yes'
      >>> print(bool_env('GWPY_VALUE'))
      True
      >>> os.environ['GWPY_VALUE'] = 'something else'
      >>> print(bool_env('GWPY_VALUE'))
      False
      >>> print(bool_env('GWPY_VALUE2'))
      False