Calculated variables

When and Why to Use

Use these to save calculated values into your survey data so they show up in reporting, just like answers to real questions.

store_value() saves a single value (like a derived age or score) as a named calculated variable
store_values() saves a list of values as a calculated multi-select variable

Common use cases include:

Calculating age from birth year
Storing a derived score

For survey logic — branching, filtering, termination — keep using normal Python variables instead of retrieving stored reporting values. Both functions also return the stored value, so you can store a value and keep working with it in one step.

`store_value(name, value, tags)`

Stores a single scalar value as a calculated variable. Returns the stored value as a typed response value (StringResponse, IntResponse, or BoolResponse).

Parameter	Type	Required	Description
name	str	yes	Name to assign to the stored value
value	str, int, or bool	yes	Value to store, often calculated from a previous answer
`tags`	s.tag()	no	Used for grouping and metadata in reporting

`store_values(name, values, tags)`

Stores a list of values as a calculated multi-select variable — useful when the derived value naturally has more than one entry, such as a set of brands a respondent qualifies for, or a list of segments they belong to. Returns the stored list as a ListResponse.

Parameter	Type	Required	Description
name	str	yes	Name to assign to the stored values
values	list of str, int, or bool	yes	List of values to store
`tags`	s.tag()	no	Used for grouping and metadata in reporting

Example Code

Single value:

python
from datetime import datetime
from survey import Survey
s = Survey(**globals())

birth_year = s.numeric_question("What year were you born in?", min_max=(1920, 2020))

# Keep the calculated value in a normal Python variable for survey logic...
age = datetime.now().year - birth_year

# ...and store it so it also appears in reporting.
s.store_value("age", age)

s.terminate_if(age < 18, "Sorry, this survey is for adults 18 and older.")

List of values:

python
from survey import Survey
s = Survey(**globals())

known = s.multi_select_question(
    "Which brands have you heard of?",
    options=["Acme", "Globex", "Initech", "Umbrella"],
)
considering = s.multi_select_question(
    "Which would you consider buying?",
    options=known,
)

# Save the intersection as a derived multi-select variable.
# (The sandbox does not allow the set() builtin, so use a comprehension.)
s.store_values("aware_and_considering",
               [brand for brand in known if brand in considering],
               tags=s.tag(source="derived"))

Notes

store_value can be used multiple times to keep track of intermediate calculations
store_values produces a multi-select variable in reporting, just like a real multi-select question would
For survey logic, keep using normal Python variables (as in the examples above) rather than retrieving stored reporting values
You can apply tags for each stored value to categorize them in your reporting schema