def std(arg, where=None, how='sample'):
    expr = _ops.StandardDev(arg, where, how).to_expr()
    expr = expr.name('std')
    return expr
Test that the m2m_changed signal has a correct database arg (#13552)
dataset/ETHPy150Open cloudera/ibis/ibis/expr/api.py/std--crossover with--dataset/ETHPy150Open django/django/tests/multiple_database/tests.py/SignalTests.test_database_arg_m2m