test_import¶

test_import(name, same_as=True, not_imported_msg=None, incorrect_as_msg=None, state=None)¶

Test import.

Test whether an import statement is used the same in the student’s environment as in the solution environment.

Parameters:

name (str) – the name of the package that has to be checked.
same_as (bool) – if false, the alias of the package doesn’t have to be the same. Defaults to True.
not_imported_msg (str) – feedback message when the package is not imported.
incorrect_as_msg (str) – feedback message if the alias is wrong.

Example:

Student code:

import numpy as np
import pandas as pa

Solution code:

import numpy as np
import pandas as pd

SCT:

test_import("numpy")  # pass
test_import("pandas") # fail
test_import("pandas", same_as = False) # pass

    def test_import(name,
                    same_as=True,
                    not_imported_msg=None,
                    incorrect_as_msg=None):

With test_import you can test whether a student correctly imported a certain package. As an option, you can also specify whether or not the same alias should be used.

Python features many ways to import packages. All of these different methods revolve around the import, from and as keywords. Suppose you want students to import matplotlib.pyplot as plt (the common way of importing the plotting tools in matplotlib. A possible solution of your exercises could be the following:

    *** =solution
    ```{python}
    # Import plotting tools
    import matplotlib.pyplot as plt
    ```

Below is a possible SCT for this exercise:

    *** =sct
    ```{python}
    test_import("matplotlib.pyplot")
    success_msg("You nailed it!")
    ```

Here, test_import will parse both the student’s submission as well as the solution, and figure out which packages were imported and how. Next, it checks if the matplotlib.pyplot package was imported and under which alias. If the student did this and imported it as plt, all is good. If, however, the student submitted import matplotlib (import entire package instead of module) or import matplotlib.pyplot as pppplot (incorrect alias), test_import() will fail and generate the appropriate messages.

As usual, you can override these messages with your own:

    *** =sct
    ```{python}
    test_import("matplotlib.pyplot"),
                            not_imported_msg = "You can import pyplot by using `import matplotlib.pyplot`.",
                            incorrect_as_msg = "You should set the correct alias for `matplotlib.pyplot`, import it `as plt`.")
    success_msg("You nailed it!")
    ```

With same_as, you can control whether or not the alias should be exactly the same. By default same_as=True, so the alias (plt in the example) should also be used by student. If you set it to False:

    *** =sct
    ```{python}
    test_import("matplotlib.pyplot", same_as=False)
    success_msg("You nailed it!")
    ```

The SCT will also pass if the student uses import matplotlib.pyplot as pppplot, a submission that wouldn’t be accepted if same_as=True.