Ejemplo n.º 1
0
def execute_until_in_scope(
    expr,
    scope: Scope,
    timecontext: Optional[TimeContext] = None,
    aggcontext=None,
    clients=None,
    post_execute_=None,
    **kwargs,
) -> Scope:
    """Execute until our op is in `scope`.

    Parameters
    ----------
    expr : ibis.expr.types.Expr
    scope : Scope
    timecontext : Optional[TimeContext]
    aggcontext : Optional[AggregationContext]
    clients : List[ibis.client.Client]
    kwargs : Mapping
    """
    # these should never be None
    assert aggcontext is not None, 'aggcontext is None'
    assert clients is not None, 'clients is None'
    assert post_execute_ is not None, 'post_execute_ is None'

    # base case: our op has been computed (or is a leaf data node), so
    # return the corresponding value
    op = expr.op()
    if scope.get_value(op, timecontext) is not None:
        return scope
    if isinstance(op, ops.Literal):
        # special case literals to avoid the overhead of dispatching
        # execute_node
        return Scope(
            {
                op:
                execute_literal(
                    op, op.value, expr.type(), aggcontext=aggcontext, **kwargs)
            },
            timecontext,
        )

    # figure out what arguments we're able to compute on based on the
    # expressions inputs. things like expressions, None, and scalar types are
    # computable whereas ``list``s are not
    computable_args = [arg for arg in op.inputs if is_computable_input(arg)]

    # pre_executed_states is a list of states with same the length of
    # computable_args, these states are passed to each arg
    if timecontext:
        arg_timecontexts = compute_time_context(
            op,
            num_args=len(computable_args),
            timecontext=timecontext,
            clients=clients,
        )
    else:
        arg_timecontexts = [None] * len(computable_args)

    pre_executed_scope = pre_execute(
        op,
        *clients,
        scope=scope,
        timecontext=timecontext,
        aggcontext=aggcontext,
        **kwargs,
    )

    new_scope = scope.merge_scope(pre_executed_scope)

    # Short circuit: if pre_execute puts op in scope, then we don't need to
    # execute its computable_args
    if new_scope.get_value(op, timecontext) is not None:
        return new_scope

    # recursively compute each node's arguments until we've changed type.
    # compute_time_context should return with a list with the same length
    # as computable_args, the two lists will be zipping together for
    # further execution
    if len(arg_timecontexts) != len(computable_args):
        raise com.IbisError(
            'arg_timecontexts differ with computable_arg in length '
            f'for type:\n{type(op).__name__}.')

    scopes = [
        execute_until_in_scope(
            arg,
            new_scope,
            timecontext=timecontext,
            aggcontext=aggcontext,
            post_execute_=post_execute_,
            clients=clients,
            **kwargs,
        ) if hasattr(arg, 'op') else Scope({arg: arg}, timecontext)
        for (arg, timecontext) in zip(computable_args, arg_timecontexts)
    ]

    # if we're unable to find data then raise an exception
    if not scopes and computable_args:
        raise com.UnboundExpressionError(
            'Unable to find data for expression:\n{}'.format(repr(expr)))

    # there should be exactly one dictionary per computable argument
    assert len(computable_args) == len(scopes)

    new_scope = new_scope.merge_scopes(scopes)
    # pass our computed arguments to this node's execute_node implementation
    data = [
        new_scope.get_value(arg.op(), timecontext)
        if hasattr(arg, 'op') else arg for arg in computable_args
    ]

    result = execute_node(
        op,
        *data,
        scope=scope,
        timecontext=timecontext,
        aggcontext=aggcontext,
        clients=clients,
        **kwargs,
    )
    computed = post_execute_(op, result, timecontext=timecontext)
    return Scope({op: computed}, timecontext)
Ejemplo n.º 2
0
def execute_window_op(
    op,
    data,
    window,
    scope: Scope = None,
    timecontext: Optional[TimeContext] = None,
    aggcontext=None,
    clients=None,
    **kwargs,
):
    if window.how == "range" and any(
            not isinstance(ob.type(), (dt.Time, dt.Date, dt.Timestamp))
            for ob in window._order_by):
        raise NotImplementedError(
            "The pandas backend only implements range windows with temporal "
            "ordering keys")
    operand = op.expr
    # pre execute "manually" here because otherwise we wouldn't pickup
    # relevant scope changes from the child operand since we're managing
    # execution of that by hand
    operand_op = operand.op()

    adjusted_timecontext = None
    if timecontext:
        arg_timecontexts = compute_time_context(op,
                                                timecontext=timecontext,
                                                clients=clients,
                                                scope=scope)
        # timecontext is the original time context required by parent node
        # of this Window, while adjusted_timecontext is the adjusted context
        # of this Window, since we are doing a manual execution here, use
        # adjusted_timecontext in later execution phases
        adjusted_timecontext = arg_timecontexts[0]

    pre_executed_scope = pre_execute(
        operand_op,
        *clients,
        scope=scope,
        timecontext=adjusted_timecontext,
        aggcontext=aggcontext,
        **kwargs,
    )
    if scope is None:
        scope = pre_executed_scope
    else:
        scope = scope.merge_scope(pre_executed_scope)
    (root, ) = op.root_tables()
    root_expr = root.to_expr()

    data = execute(
        root_expr,
        scope=scope,
        timecontext=adjusted_timecontext,
        clients=clients,
        aggcontext=aggcontext,
        **kwargs,
    )
    following = window.following
    order_by = window._order_by

    if (order_by and following != 0
            and not isinstance(operand_op, ops.ShiftBase)):
        raise com.OperationNotDefinedError(
            'Window functions affected by following with order_by are not '
            'implemented')

    group_by = window._group_by
    grouping_keys = [
        key_op.name if isinstance(key_op, ops.TableColumn) else execute(
            key,
            scope=scope,
            clients=clients,
            timecontext=adjusted_timecontext,
            aggcontext=aggcontext,
            **kwargs,
        ) for key, key_op in zip(group_by,
                                 map(operator.methodcaller('op'), group_by))
    ]

    order_by = window._order_by
    if not order_by:
        ordering_keys = []

    post_process: Callable[
        [Any, pd.DataFrame, List[str], List[str], Optional[TimeContext]],
        pd.Series, ]
    if group_by:
        if order_by:
            (
                sorted_df,
                grouping_keys,
                ordering_keys,
            ) = util.compute_sorted_frame(
                data,
                order_by,
                group_by=group_by,
                timecontext=adjusted_timecontext,
                **kwargs,
            )
            source = sorted_df.groupby(grouping_keys, sort=True)
            post_process = _post_process_group_by_order_by
        else:
            source = data.groupby(grouping_keys, sort=False)
            post_process = _post_process_group_by
    else:
        if order_by:
            source, grouping_keys, ordering_keys = util.compute_sorted_frame(
                data, order_by, timecontext=adjusted_timecontext, **kwargs)
            post_process = _post_process_order_by
        else:
            source = data
            post_process = _post_process_empty

    # Here groupby object should be add to the corresponding node in scope
    # for execution, data will be overwrite to a groupby object, so we
    # force an update regardless of time context
    new_scope = scope.merge_scopes(
        [
            Scope({t: source}, adjusted_timecontext)
            for t in operand.op().root_tables()
        ],
        overwrite=True,
    )

    aggcontext = get_aggcontext(
        window,
        scope=scope,
        operand=operand,
        parent=source,
        group_by=grouping_keys,
        order_by=ordering_keys,
        **kwargs,
    )
    result = execute(
        operand,
        scope=new_scope,
        timecontext=adjusted_timecontext,
        aggcontext=aggcontext,
        clients=clients,
        **kwargs,
    )
    result = post_process(
        result,
        data,
        ordering_keys,
        grouping_keys,
        adjusted_timecontext,
    )
    assert len(data) == len(
        result
    ), 'input data source and computed column do not have the same length'

    # trim data to original time context
    result = trim_window_result(result, timecontext)
    return result