def __init__(self, read=False, add=False, create=False, write=False, <EOL>delete=False, _str=None):
if not _str:<EOL><INDENT>_str = '<STR_LIT>'<EOL><DEDENT>self.read = read or ('<STR_LIT:r>' in _str)<EOL>self.add = add or ('<STR_LIT:a>' in _str)<EOL>self.create = create or ('<STR_LIT:c>' in _str)<EOL>self.write = write or ('<STR_LIT:w>' in _str)<EOL>self.delete = delete or ('<STR_LIT:d>' in _str)<EOL>
:param bool read:
    Read the content, properties, metadata and block list. Use the blob as 
    the source of a copy operation.
:param bool add:
    Add a block to an append blob.
:param bool create:
    Write a new blob, snapshot a blob, or copy a blob to a new blob.
:param bool write: 
    Create or write content, properties, metadata, or block list. Snapshot 
    or lease the blob. Resize the blob (page blob only). Use the blob as the 
    destination of a copy operation within the same account.
:param bool delete: 
    Delete the blob.
:param str _str: 
    A string representing the permissions.