print 'length of angle list not correct'+\ '({0} instead of {1})'.format(len(angle), len(self.z)) should be print 'length of angle list not correct'+\ '({0} instead of {1})'.format(len(angle), len(self.Z.z))
print 'length of angle list not correct'+
'({0} instead of {1})'.format(len(angle), len(self.z))
should be
print 'length of angle list not correct'+
'({0} instead of {1})'.format(len(angle), len(self.Z.z))