Data Types in Python

Data types specify the kind of value a variable can hold. Python is a dynamically-typed language, meaning that you don’t need to declare a variable’s type explicitly; Python infers the type based on the assigned value.

To determine the type of a variable, you can use the built-in type() function.

Python’s Built-in Data Types

Python provides the following built-in data types:

• Text type: str

  The string (str) data type is used for textual data. You can create a string by enclosing characters within single or double quotes.

  a = "Hello World!"
  print(type(a))
   
  #output: <class 'str'>

• Numeric type: int, float, complex

  Python provides three types of numeric values:

  int: Integer numbers (positive or negative).

  float: Floating-point numbers (decimal numbers).

  complex: Complex numbers, with a real and imaginary part.

  a = 5 #int
  b = 5.5 #float
  c = 5j #complex
   
  print(type(a))  # Output: <class 'int'>
  print(type(b))  # Output: <class 'float'>
  print(type(c))  # Output: <class 'complex'>

• Boolean type: bool

  The boolean (bool) data type is used to represent one of two possible values: True or False. It is commonly used in conditions and loops.

  a = True
  print(type(a))
   
  #output: <class 'bool'>

• Sequence type: list ,tuple ,range

  Python has three built-in sequence types:

  list: Ordered, mutable collections of items (can hold different data types).

  tuple: Ordered, immutable collections of items.

  range: Represents a sequence of numbers, often used in for-loops.

  We will explore these data types in much more detail as we progress.

  a = ["one", "two", "three"] #list
  b = ("one", "two", "three") #tuple
  c = range(5) #range
   
  print(type(a))  # Output: <class 'list'>
  print(type(b))  # Output: <class 'tuple'>
  print(type(c))  # Output: <class 'range'>

• Set type: set, frozenset

  Sets are unordered collections of unique items.

  set: Mutable set.

  frozenset: Immutable set.

  a = {"one", "two", "three"} #set
  b = frozenset({"one", "two", "three"}) #frozenset
   
  print(type(a))  # Output: <class 'set'>
  print(type(b))  # Output: <class 'frozenset'>

• Mapping type: dict

  A dictionary (dict) is an unordered collection of key-value pairs. The keys must be unique, and the values can be any data type.

  a = {"name" : "John", "age" : 25}
  print(type(a))  # Output: <class 'dict'>

• None type: NoneType

  The None type represents the absence of a value or a null value. It is commonly used to signify that a variable has no value assigned.

  a = None
  print(type(a))  # Output: <class 'NoneType'>

• Binary types: bytes, bytearray, memoryview

  These types are used for handling binary data.

  bytes: Immutable sequence of bytes.

  bytearray: Mutable sequence of bytes.

  memoryview: A view object that references data in bytes or bytearray without copying.

  a = b"Hello"               # bytes  
  b = bytearray(b"Hello")    # bytearray
  c = memoryview(b"Hello")   # memoryview
   
  print(type(a))  # Output: <class 'bytes'>
  print(type(b))  # Output: <class 'bytearray'>
  print(type(c))  # Output: <class 'memoryview'>
   

Summary of Data Types in Python

Data Type	Description	Example
str	String type for textual data	"Hello World!"
int	Integer type for whole numbers	5
float	Float type for decimal numbers	5.5
complex	Complex number type (real + imaginary part)	5j
bool	Boolean type, represents True or False	True or False
list	Mutable sequence of items	["one", "two", "three"]
tuple	Immutable sequence of items	("one", "two", "three")
range	Sequence of numbers (usually used in loops)	range(5)
set	Unordered collection of unique items	{"one", "two", "three"}
frozenset	Immutable set	frozenset({"one", "two", "three"})
dict	Key-value pair collection	{"name": "John", "age": 25}
NoneType	Represents no value (None)	None
bytes	Immutable binary data	b"hello"
bytearray	Mutable binary data	bytearray(b"hi")
memoryview	View of binary data	memoryview(b"hi")

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