Types that can be called as a function.
Examples of entities that can be called:
- Built-in and custom functions ;
- Built-in and custom methods;
- Generator functions;
- Classes (both classic and new style); li>
- Instances of classes.
Types that support the ability to call them as a function accept a set of arguments, which, however, can be empty.
Call always is followed by the return of some value (possibly None) unless an exception is thrown.
# Call the generic function len ()
# passing a list as the only argument
# and returning the computed length of the list.
len ( [1, 2, 3]) # 3
The details of how the value is calculated depends on the type of object being called.