def test_whos():
 class A(object, ):
  def __repr__(self):
   raise Exception()
 _ip.user_ns['a'] = A()
 _ip.magic('whos')

def test_whos ( ) : class A ( object , ) : def __repr__ ( self ) : raise Exception ( ) _ip . user_ns [ 'a' ] = A ( ) _ip . magic ( 'whos' )
check that whos is protected against objects where repr() fails .