pythonwhat/checks/check_object.py
def check_keys(state, key, missing_msg=None, expand_msg=None):
    """Check whether an object (dict, DataFrame, etc) has a key.

    ``check_keys()`` can currently only be used when chained from ``check_object()``, the function that is
    used to 'zoom in' on the object of interest.

    Args:
        key (str): Name of the key that the object should have.
        missing_msg (str): When specified, this overrides the automatically generated
            message in case the key does not exist.
        expand_msg (str): If specified, this overrides any messages that are prepended by previous SCT chains.
        state (State): The state that is passed in through the SCT chain (don't specify this).

    :Example:

        Student code and solution code::

            x = {'a': 2}

        SCT::

            # Verify that x contains a key a
            Ex().check_object('x').check_keys('a')

            # Verify that x contains a key a and a is correct.
            Ex().check_object('x').check_keys('a').has_equal_value()

    """

    state.assert_is(["object_assignments"], "is_instance", ["check_object", "check_df"])

    if missing_msg is None:
        missing_msg = "There is no {{ 'column' if 'DataFrame' in parent.typestr else 'key' }} `'{{key}}'`."
    if expand_msg is None:
        expand_msg = "Did you correctly set the {{ 'column' if 'DataFrame' in parent.typestr else 'key' }} `'{{key}}'`? "

    sol_name = state.solution_parts.get("name")
    stu_name = state.student_parts.get("name")

    if not isDefinedCollInProcess(sol_name, key, state.solution_process):
        raise InstructorError(
            "`check_keys()` couldn't find key `%s` in object `%s` in the solution process."
            % (key, sol_name)
        )

    # check if key available
    _msg = state.build_message(missing_msg, {"key": key})
    state.do_test(
        DefinedCollProcessTest(
            stu_name, key, state.student_process, Feedback(_msg, state)
        )
    )

    def get_part(name, key, highlight):
        if isinstance(key, str):
            slice_val = ast.Str(s=key)
        else:
            slice_val = ast.parse(str(key)).body[0].value
        expr = ast.Subscript(
            value=ast.Name(id=name, ctx=ast.Load()),
            slice=ast.Index(value=slice_val),
            ctx=ast.Load(),
        )
        ast.fix_missing_locations(expr)
        return {"node": expr, "highlight": highlight}

    stu_part = get_part(stu_name, key, state.student_parts.get("highlight"))
    sol_part = get_part(sol_name, key, state.solution_parts.get("highlight"))
    append_message = {"msg": expand_msg, "kwargs": {"key": key}}
    child = part_to_child(stu_part, sol_part, append_message, state)
    return child
def check_keys(state, key, missing_msg=None, expand_msg=None):
    """Check whether an object (dict, DataFrame, etc) has a key.

    ``check_keys()`` can currently only be used when chained from ``check_object()``, the function that is
    used to 'zoom in' on the object of interest.

    Args:
        key (str): Name of the key that the object should have.
        missing_msg (str): When specified, this overrides the automatically generated
            message in case the key does not exist.
        expand_msg (str): If specified, this overrides any messages that are prepended by previous SCT chains.
        state (State): The state that is passed in through the SCT chain (don't specify this).

    :Example:

        Student code and solution code::

            x = {'a': 2}

        SCT::

            # Verify that x contains a key a
            Ex().check_object('x').check_keys('a')

            # Verify that x contains a key a and a is correct.
            Ex().check_object('x').check_keys('a').has_equal_value()

    """

    state.assert_is(["object_assignments"], "is_instance", ["check_object", "check_df"])

    if missing_msg is None:
        missing_msg = "There is no {{ 'column' if 'DataFrame' in parent.typestr else 'key' }} `'{{key}}'`."
    if expand_msg is None:
        expand_msg = "Did you correctly set the {{ 'column' if 'DataFrame' in parent.typestr else 'key' }} `'{{key}}'`? "

    sol_name = state.solution_parts.get("name")
    stu_name = state.student_parts.get("name")

    if not isDefinedCollInProcess(sol_name, key, state.solution_process):
        raise InstructorError(
            "`check_keys()` couldn't find key `%s` in object `%s` in the solution process."
            % (key, sol_name)
        )

    # check if key available
    _msg = state.build_message(missing_msg, {"key": key})
    state.do_test(
        DefinedCollProcessTest(
            stu_name, key, state.student_process, Feedback(_msg, state)
        )
    )

    def get_part(name, key, highlight):
        if isinstance(key, str):
            slice_val = ast.Str(s=key)
        else:
            slice_val = ast.parse(str(key)).body[0].value
        expr = ast.Subscript(
            value=ast.Name(id=name, ctx=ast.Load()),
            slice=ast.Index(value=slice_val),
            ctx=ast.Load(),
        )
        ast.fix_missing_locations(expr)
        return {"node": expr, "highlight": highlight}

    stu_part = get_part(stu_name, key, state.student_parts.get("highlight"))
    sol_part = get_part(sol_name, key, state.solution_parts.get("highlight"))
    append_message = {"msg": expand_msg, "kwargs": {"key": key}}
    child = part_to_child(stu_part, sol_part, append_message, state)
    return child
Check whether an object (dict, DataFrame, etc) has a key.

    ``check_keys()`` can currently only be used when chained from ``check_object()``, the function that is
    used to 'zoom in' on the object of interest.

    Args:
        key (str): Name of the key that the object should have.
        missing_msg (str): When specified, this overrides the automatically generated
            message in case the key does not exist.
        expand_msg (str): If specified, this overrides any messages that are prepended by previous SCT chains.
        state (State): The state that is passed in through the SCT chain (don't specify this).

    :Example:

        Student code and solution code::

            x = {'a': 2}

        SCT::

            # Verify that x contains a key a
            Ex().check_object('x').check_keys('a')

            # Verify that x contains a key a and a is correct.
            Ex().check_object('x').check_keys('a').has_equal_value()