Built-in Data Types
Data types are a key idea in programming.
A variable can hold many kinds of data, and what you can do with a value depends on its type.
Out of the box, Python comes with these data types, grouped by category:
Built-in data types by category
main.py
# Text Type: str
# Numeric Types: int, float, complex
# Sequence Types: list, tuple, range
# Mapping Type: dict
# Set Types: set, frozenset
# Boolean Type: bool
# Binary Types: bytes, bytearray, memoryview
# None Type: NoneType
Getting the Data Type
Pass any object to the type() function to find out its data type.
Example
Show the data type of x:
Prompt
Write a Python program that creates a variable x with value 5 and prints its data type using the type() function.
Output: complete Python program
main.py
x = 5
print(type(x))
Setting the Data Type
Python decides a variable's data type at the moment you assign it a value:
Setting data type by assignment
main.py
x = "Hello World" # str
x = 20 # int
x = 20.5 # float
x = 1j # complex
x = ["apple", "banana", "cherry"] # list
x = ("apple", "banana", "cherry") # tuple
x = range(6) # range
x = {"name" : "John", "age" : 36} # dict
x = {"apple", "banana", "cherry"} # set
x = frozenset({"apple", "banana", "cherry"}) # frozenset
x = True # bool
x = b"Hello" # bytes
x = bytearray(5) # bytearray
x = memoryview(bytes(5)) # memoryview
x = None # NoneType
Setting the Specific Data Type
When you want to choose the data type yourself, use one of these constructor functions:
Setting specific data type with constructors
main.py
x = str("Hello World") # str
x = int(20) # int
x = float(20.5) # float
x = complex(1j) # complex
x = list(("apple", "banana", "cherry")) # list
x = tuple(("apple", "banana", "cherry")) # tuple
x = range(6) # range
x = dict(name="John", age=36) # dict
x = set(("apple", "banana", "cherry")) # set
x = frozenset(("apple", "banana", "cherry")) # frozenset
x = bool(5) # bool
x = bytes(5) # bytes
x = bytearray(5) # bytearray
x = memoryview(bytes(5)) # memoryview