def isTrue(val):
 val = val.lower()
 return ((val == 'true') or (val == 't') or (val == '1') or (val == 'yes'))

def isTrue ( val ) : val = val . lower ( ) return ( ( val == 'true' ) or ( val == 't' ) or ( val == '1' ) or ( val == 'yes' ) )
determines if a textual value represents true .