test_dictionary¶

test_dictionary(name, keys=None, undefined_msg=None, not_dictionary_msg=None, key_missing_msg=None, incorrect_value_msg=None, state=None)¶: Test the contents of a dictionary.

def test_dictionary(name,
                    keys=None,
                    undefined_msg=None,
                    not_dictionary_msg=None,
                    key_missing_msg=None,
                    incorrect_value_msg=None)

Test a dictionary. Consider this function an advanced version of test_object, where you can specify messages that are explicit to test dictionaries. test_dictionary takes a step-by-step approach to checking the correspondence of the dictionary between student and solution process:

Step 1: Is the object specified in name actually defined?
Step 2: Is the object specified in name actually a dictionary?
Step 3: For each key, is the key specified in the dictionary?
Step 4: For each key, is the value corresponding to the key correct when comparing to the solution?

For Step 3 and Step 4, you can control which keys have to be tested through the keys argument. If you don’t specify this argument, test_dictionary() will look for all keys and compare the values that are specified in the corresponding dictionary in the solution process.

Example: step by step¶

Suppose you want the student to create a dictionary x, that contains three keys: "a", "b" and "c". The following solution and sct could be used for this:

*** =solution
```{python}
x = {'a': 123, 'b':456, 'c':789}
```

*** =sct
```{python}
test_dictionary('x')
```

Step 1: if the student submits an empty script, the feedback Are you sure you defined the dictionary x? will be presented. You can override this by specifying undefined_msg yourself.
Step 2: if the student submits x = 123, the feedback x is not a dictionary. will be presented. You can override this message by specifying not_dictionary_msg yourself.
Step 3: if the student submits x = {'a':123, 'b':456, 'd':78}, the feedback Have you specified a key c inside x? will be presented. You can override this by specifying key_missing_msg yourself.
Step 4: if the student submits x = {'a':123, 'b':456, 'c':78}, the feedback Have you specified the correct value for the key c inside x? will be presented. You can override this by specifying incorrect_value_msg yourself.

NOTE: Behind the scenes, pythonwhat has to fetch the value of objects from sub-processes. The required ‘dilling’ and ‘undilling’ can cause issues for exotic objects. For more information on this and possible errors that can occur, read the Processes article.