def col_op(self, j, f):
        self._mat[j::self.cols] = [f(*t) for t in list(zip(self._mat[j::self.cols], list(range(self.rows))))]
Roll back any ongoing transaction and clean the transaction state
dataset/ETHPy150Open sympy/sympy/sympy/matrices/dense.py/MutableDenseMatrix.col_op--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/backends/__init__.py/BaseDatabaseWrapper.abort