The type function is a Python built-in that returns an object’s type. Use it when runtime inspection helps a function accept different input forms, such as an integer or a list. section 10.1.1 section 10.1
Inspecting values
print(type(4)) # output: <class 'int'> print(type([4, 5])) # output: <class 'list'> section 10.1.1
Compare the returned type with a class to select behavior. In a task-filtering function, a list uses membership testing, while another value uses direct urgency comparison. section 10.1.1
Listing 10.1 Comparing an object’s type with a class
def filter_tasks(tasks, by_urgency):
if type(by_urgency) is list:
filtered = [x for x in tasks if x.urgency in by_urgency]
else:
filtered = [x for x in tasks if x.urgency == by_urgency]
return filtered
Branches on whether by_urgency is a list, then filters tasks with membership or equality. section 10.1.1
Keep these distinctions in mind:
- type(value) reports the value’s current runtime type. section 10.1.1
- Python variables can later refer to values of another type; type inspection observes that current value rather than fixing the variable. section 6.3.1
- Use isinstance for a more flexible instance check when superclass relationships matter. section 10.6
