These are examples of some of the most common built-in types:
| Type | Description |
|---|---|
int |
integer |
float |
floating point number |
bool |
boolean value (subclass of int) |
str |
string (unicode) |
bytes |
8-bit string |
object |
an arbitrary object (object is the common base class) |
List[str] |
list of str objects |
Tuple[int, int] |
tuple of two int objects (Tuple[()] is the empty tuple) |
Tuple[int, ...] |
tuple of an arbitrary number of int objects |
Dict[str, int] |
dictionary from str keys to int values |
Iterable[int] |
iterable object containing ints |
Sequence[bool] |
sequence of booleans (read-only) |
Mapping[str, int] |
mapping from str keys to int values (read-only) |
Any |
dynamically typed value with an arbitrary type |
The type Any and type constructors such as List, Dict,
Iterable and Sequence are defined in the :py:mod:`typing` module.
The type Dict is a generic class, signified by type arguments within
[...]. For example, Dict[int, str] is a dictionary from integers to
strings and Dict[Any, Any] is a dictionary of dynamically typed
(arbitrary) values and keys. List is another generic class. Dict and
List are aliases for the built-ins dict and list, respectively.
Iterable, Sequence, and Mapping are generic types that correspond to
Python protocols. For example, a str object or a List[str] object is
valid when Iterable[str] or Sequence[str] is expected. Note that even
though they are similar to abstract base classes defined in
:py:mod:`collections.abc` (formerly collections), they are not identical. In
particular, prior to Python 3.9, the built-in collection type objects do not
support indexing.
In Python 3.9 and later, built-in collection type objects support indexing. This means that you can use built-in classes or those from :py:mod:`collections.abc` instead of importing from :py:mod:`typing`. See :ref:`generic-builtins` for more details.