Home > Article > Backend Development > PYTHON-FUNDAMENTALS: CONSTANTS, VARIABLES AND DATA TYPES
hi,everyody
I am kavin. I am going to write which I learnt I my class.
A variable in Python is a symbolic name that references or points to an object. Once a variable is assigned a value, it can be used to refer to that value throughout the program. Variables act as containers for storing data values.
1.Start with a letter or an underscore.
2.Followed by letters, digits, or underscores.
3.Case-sensitive
4.Don't use Python Keywords
Examples of Valid Variable Names:
my_variable
variable1
_hidden_variable
userName
In Python, the assignment operator = is used to assign values to variables. The syntax is straightforward: variable_name = value.
eg:
>>>name="kavin" >>>print(name) >>>kavin
Python allows you to assign values to multiple variables in a single line. This can make your code more concise and readable.
eg:
>>>a,b,c=1,2,3 >>>print(a,b,c)
Python is a dynamically typed language, which means you don’t need to declare the type of a variable when assigning a value to it. The type is inferred at runtime based on the assigned value.
eg:
>>>my_variable="10" >>>my_variable is an integer
You can check the type of a variable using the type() function.
eg:
>>>type("hello") >>><class'str'>
In Python, constants are variables whose values are not meant to change. By convention, constants are typically written in all uppercase letters with underscores separating words.
eg:
>>>PI=22/7
Data types are the different kinds of values that you can store and work with.
1.Numeric Types
*Integer (int): Whole numbers.
>>>value=23
*Float (float): Decimal numbers.
>>>value=23.5
*Complex (complex): Complex numbers.
>>>value=2+3j
String (str): Sequence of characters.
eg:
>>>message="hello mac"
Boolean (bool): Represents True or False.
eg:
>>>my_project=True
NoneType: Represents the absence of a value
eg:
>>>result=none
*List (list): Ordered, mutable collection
eg:
>>>fruits=[apple,cherry,mango]
*Tuple (tuple): Ordered, immutable collection.
eg:
>>>coordinates(3,4)
*Range (range): Sequence of numbers.
eg:
>>>number=range(1,10)
Dictionary (dict): Unordered, mutable collection of key-value pairs.
eg:
>>>person={"name":"kavin","url":"https://www.kavin.com"}
Set (set): Unordered collection of unique elements.
Eg:
>>>unique_number={2,3,4}
Frozenset (frozenset): Immutable set.
eg:
>>>frozen_set=frozena([2,3,4])
Syntax: type(variable_name)
eg:
>>>name="kavin" >>>print(type(name)) >>> <class'int'>
this is the things which i learnt in the class of Variables, Constants and Data Types.
Thank You
The above is the detailed content of PYTHON-FUNDAMENTALS: CONSTANTS, VARIABLES AND DATA TYPES. For more information, please follow other related articles on the PHP Chinese website!