How to show multiple items on one page

[slussinator]

I would like to elegantly show multiple items out of a big item pool on several pages. I have 60 items and would like to show 5 per page. Here is my solution so far. The minimal code doesn't quite work the way the proper experiment does, but for these purposes it should do.
To create multiple pages with only 5 items each I have to repeat the same code several times (12 times for 60 items) and add each page at the bottom. This works but perhaps there is a more elegant way!

list_items = [
{"name": "1", "toplab": "This is item 1."},
{"name": "2", "toplab": "This is item 2."},
{"name": "3", "toplab": "This is item 3."},
{"name": "4", "toplab": "This is item 4."},
{"name": "5", "toplab": "This is item 5."},
{"name": "6", "toplab": "This is item 6."},
{"name": "7", "toplab": "This is item 7."},
{"name": "8", "toplab": "This is item 8."},
{"name": "9", "toplab": "This is item 9."},
{"name": "10", "toplab": "This is item 10."}
]

list_choices = [
"1",
"2",
"3",
"4",
"5",
]

list_labels = [
"not at all",
"seldomnly",
"every now and then",
"often",
"always"
]

@exp.member
class questionnaire(al.Section):
title = "Questionnaire"

def on_exp_access(self):
    first_5 = al.Page(name="first_5")
    first_5 += al.ButtonLabels(list_labels, leftlab=" ", button_style="btn-secondary")

    for kwargs in list_items[0:5]:
        first_5 += al.VerticalSpace()
        first_5 += al.SingleChoiceButtons(list_choices,
                                          leftlab=f"{kwargs.get('toplab')}",
                                          name=f"items{kwargs.get('name')}",
                                          width="full",
                                          force_input=True,
                                          font_size="small"
                                          )

    second_5 = al.Page(name="second_5")
    second_5 += al.ButtonLabels(list_labels, leftlab=" ", button_style="btn-secondary")

    for kwargs in list_items[5:10]:
        second_5 += al.VerticalSpace()
        second_5 += al.SingleChoiceButtons(list_choices,
                                           leftlab=f"{kwargs.get('toplab')}",
                                           name=f"items{kwargs.get('name')}",
                                           width="full",
                                           force_input=True,
                                           font_size="small"
                                           )

    self += first_5
    self += second_5

if name == "main":
exp.run()

[ctreffe]

Hey there, let's start with a couple of minor remarks on your code example, before we look at ways to shorten it:

1. I would recommend you to use camel case for class names, which is common practice in Python. Hence, I will rename your class questionnaire into Questionnaire.
2. I think using kwargs as a variable name can lead to confusion, especially when you name a dicitonary kwargs and use kwargs.get(), as you would for **kwargs (which is a magic variable used in function definitions). I will use item as variable name, instead.
3. I would also recommend not to use list_items, list_choices, and list_labels as global variables (by defining them on the top of your script), but instead to define them inside your on_exp_access() function. This should not be a problem since you probably don't want to use them outside of this function.
4. Alfred requires the names of sections, pages, elements, etc. to start with a letter. Therefore, I will rename your items in list_items.
5. You probably wish to unpack list_choices and list_labels when using them in the elements you create. Therefore, you need to add * as a prefix in your code (otherwise your labels and likert buttons will show a list instead of each single item).

With the above changes and some minor adjustments, your code will work nicely to split up a larger number of items over multiple pages:

import alfred3 as al
exp = al.Experiment()


@exp.member
class Questionnaire(al.Section):
    title = "Questionnaire"

    def on_exp_access(self):
        list_items = [
            {"name": "i1", "toplab": "This is item 1."},
            {"name": "i2", "toplab": "This is item 2."},
            {"name": "i3", "toplab": "This is item 3."},
            {"name": "i4", "toplab": "This is item 4."},
            {"name": "i5", "toplab": "This is item 5."},
            {"name": "i6", "toplab": "This is item 6."},
            {"name": "i7", "toplab": "This is item 7."},
            {"name": "i8", "toplab": "This is item 8."},
            {"name": "i9", "toplab": "This is item 9."},
            {"name": "i10", "toplab": "This is item 10."}
        ]

        list_choices = ["1", "2", "3", "4", "5"]

        list_labels = ["not at all", "seldomnly", "every now and then", "often", "always"]

        first_5 = al.Page(name="first_5")
        first_5 += al.ButtonLabels(*list_labels, leftlab=" ", button_style="btn-secondary")

        for item in list_items[0:5]:
            first_5 += al.VerticalSpace()
            first_5 += al.SingleChoiceButtons(*list_choices,
                                              leftlab=item.get('toplab'),
                                              name=item.get('name'),
                                              width="full",
                                              force_input=True,
                                              font_size="small"
                                              )

        second_5 = al.Page(name="second_5")
        second_5 += al.ButtonLabels(*list_labels, leftlab=" ", button_style="btn-secondary")

        for item in list_items[5:10]:
            second_5 += al.VerticalSpace()
            second_5 += al.SingleChoiceButtons(*list_choices,
                                              leftlab=item.get('toplab'),
                                              name=item.get('name'),
                                              width="full",
                                              force_input=True,
                                              font_size="small"
                                              )

        self += first_5
        self += second_5

if __name__ == "__main__":
    exp.run()

However, there is a way to shorten your code by combining a for-loop and a while-loop. With this, we can use the pop() function to access and at the sime time remove items from the item list, and our while-loop will only run until item_list is empty:

import alfred3 as al
exp = al.Experiment()

@exp.member
class Questionnaire(al.Section):
    title = "Questionnaire"

    def on_exp_access(self):
        list_items = [
            {"name": "i1", "toplab": "This is item 1."},
            {"name": "i2", "toplab": "This is item 2."},
            {"name": "i3", "toplab": "This is item 3."},
            {"name": "i4", "toplab": "This is item 4."},
            {"name": "i5", "toplab": "This is item 5."},
            {"name": "i6", "toplab": "This is item 6."},
            {"name": "i7", "toplab": "This is item 7."},
            {"name": "i8", "toplab": "This is item 8."},
            {"name": "i9", "toplab": "This is item 9."},
            {"name": "i10", "toplab": "This is item 10."}
        ]

        list_choices = ["1", "2", "3", "4", "5"]

        list_labels = ["not at all", "seldomnly", "every now and then", "often", "always"]

        count = 1
        while list_items:
            page = al.Page(name=f"questionnaire_{count}")
            page += al.ButtonLabels(*list_labels, leftlab=" ", button_style="btn-secondary")

            for i in range(5):
                item = list_items.pop(0)  # Return and remove the first list item

                page += al.VerticalSpace()
                page += al.SingleChoiceButtons(
                    *list_choices,
                    leftlab=item['toplab'],
                    name=item['name'],
                    width="full",
                    force_input=True,
                    font_size="small"
                )

            self += page
            count += 1


if __name__ == "__main__":
    exp.run()

Further explanation: I use the new variable count to set the page name in each iteration of my while loop. The loop itself will only run until there are no items left in item_list and in each iteration of the for-loop, I remove an item from the list. On first sight, this might seem a little complex, but there is a big advantage to this variant, other than not needing to copy and paste the for-loop: By adding two lines of code, I can make the example work for a variable number of items:

import alfred3 as al
exp = al.Experiment()

@exp.member
class Questionnaire(al.Section):
    title = "Questionnaire"

    def on_exp_access(self):
        list_items = [
            {"name": "i1", "toplab": "This is item 1."},
            {"name": "i2", "toplab": "This is item 2."},
            {"name": "i3", "toplab": "This is item 3."},
            {"name": "i4", "toplab": "This is item 4."},
            {"name": "i5", "toplab": "This is item 5."},
            {"name": "i6", "toplab": "This is item 6."},
            {"name": "i7", "toplab": "This is item 7."},
            {"name": "i8", "toplab": "This is item 8."},
            {"name": "i9", "toplab": "This is item 9."},
            {"name": "i10", "toplab": "This is item 10."}
        ]

        list_choices = ["1", "2", "3", "4", "5"]

        list_labels = ["not at all", "seldomnly", "every now and then", "often", "always"]

        count = 1
        while list_items:
            page = al.Page(name=f"questionnaire_{count}")
            page += al.ButtonLabels(*list_labels, leftlab=" ", button_style="btn-secondary")

            for i in range(5):
                # The following two lines will skip the remaining iterations when the
                # item list runs out of items, giving the code way more flexibility.
                if not list_items:
                    continue

                item = list_items.pop(0)  # Return and remove the first list item

                page += al.VerticalSpace()
                page += al.SingleChoiceButtons(
                    *list_choices,
                    leftlab=item['toplab'],
                    name=item['name'],
                    width="full",
                    force_input=True,
                    font_size="small"
                )

            self += page
            count += 1


if __name__ == "__main__":
    exp.run()

With this final variant, you can change the number in range() to any number you like and you can add or remove items from item_list without having to change anything else. The combined while- and for-loops will run until all items in item_list have been added.

[slussinator]

Thank you, this works perfectly!
On a side note: I had all my items on an external file (hence the kwargs variable). For those interested: the code still works even if the items are not defined within the def_on_exp_access.