hi,everyody
I am kavin. I am going to write which I learnt I my class.
Variables
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.
How to name a variables
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
Assigning Values to Variables
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
Multiple Assignments
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)
Variable Types
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'>
Constants
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
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
2. Text Type
String (str): Sequence of characters.
eg:
>>>message="hello mac"
3. Boolean Type
Boolean (bool): Represents True or False.
eg:
>>>my_project=True
4. None Type
NoneType: Represents the absence of a value
eg:
>>>result=none
5. Sequence Types
*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)
6. Mapping Type
Dictionary (dict): Unordered, mutable collection of key-value pairs.
eg:
>>>person={"name":"kavin","url":"https://www.kavin.com"}
7.Set Type
Set (set): Unordered collection of unique elements.
Eg:
>>>unique_number={2,3,4}
Frozenset (frozenset): Immutable set.
eg:
>>>frozen_set=frozena([2,3,4])
Checking Data Type
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
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