python

 python

 

Is a both compiled & interpreted object-oriented high-level programing language with dynamic sensa tics.

 Python is one of the easiest yet most useful programming languages

Competitive Programming, Web Development, and creating software

Today, Python is used in all kinds of development from game development, basic programming, and scripting to large and complex software development. 

 

Creator of python

Python was developed by 1991 by a data programmer Guido Ven Rossum

Name python the British Sketch comedy Series Monty python   flying cercus or which he was big fan .’

Python 2.o was released in 2000 python 3.0  released in 200008

It has a large community support and is rich in the library, having all kinds of frameworks for backend, frontend 

Feature:

OOPs Dynamically

type GUI programming support extensible large stand and library free & open Source

Cross platform language interpreted 

Easy to learn & us expressive language

Application

Data Science

Web Development

Data engineering

ML

AI

Data analytics

First program in python

To  call first function in python we just need to write print followed by parentheses () and various inside question marks

INPUT:

Print (“hello world”)

Output: hello World
using multiple line in python

These are two methods to write statement in multiple line

To print multiple  line in python triple question are used \n backspace is used to insert Something in the  next line
print(“hello world”)

print(“hello \n world”)

Comment in python:

Single line Comment:

To add single line Comment #hash is used python completely ignore anything written after #

 # in this program I will add two number

Multiple line

Variable:

 

In a place holder which container that hole data inside it as a value

INPUT The world:

A =”hello world”

Print(a)

Output:

Hello world

 

Rule of Variable:

Python is a case sensitive language therefore variable name are sensitive as well

A =” hello”

Print(a)

I will throw an error as a case used here for variable name                

Make sure to not use space while creating a variable one we can use underscore to separate a name while writing a variable.

A variable name should never start  with a number  or Special Symbol

 

Data type & use input:

Text type: string(str)

Numeric type( int, float, complex

Sequence type: list tuple & Range

Mapping: Dictionaries (Duct)

Set type: set, frezenest

Bolean type:  bool

Byte: byte array ,  type  view & Binary  type

User input: to ask the input from the user default data type string

Input: name : input(“enter your name here”)

Print(name)

Example:

Name = (input (“enter your name “))

Print (name)

Age = (input (“enter your age  “))

Print (age)

Type Casting:

Subtype:

Conversion of one data type to another data type 

Thera are two types of caseing:

Input type conversion:  when python itself convert one data type to another

Explicit type conversion when user convert one data type to another.

Operators:

 Indicate what operation is to be perform while operands indicates and what the action or the operation should be performed

In Python programming, Operators in general are used to perform operations on values and variables. These are standard symbols used for logical and arithmetic operations.

X+y

 

OPERATORS: These are the special symbols. Eg- + , * , /, etc.

OPERAND: It is the value on which the operator is applied.

 

In this given expression x , y &0  are operand

Types of operators:

Asthmatic operators:  

are used to perform basic mathematical operations like addition, subtraction, multiplication and division.

Comparison operators:

compares the values. It either returns True or False according to the condition.

Logical operator:

 perform Logical AND, Logical OR and Logical NOT operations. It is used to combine conditional statements.

 

The precedence of Logical Operators in Python is as follows:

1.    Logical not

2.    logical and

3.    logical or

 

 

 

Bitwise operators:

act on bits and perform bit-by-bit operations. These are used to operate on binary numbers.

Bitwise Operators in Python are as follows:

1.    Bitwise NOT

2.    Bitwise Shift

3.    Bitwise AND

4.    Bitwise XOR

5.    Bitwise OR

 

 

Assignment operators:

re used to assign values to the variables. This operator is used to assign the value of the right side of the expression to the left side operand.

 

Identity operators:

both are used to check if two values are located on the same part of the memory. Two variables that are equal do not imply that they are identical. 

is True if the operands are identical
is not True if the operands are not identical

membership operators:

 

that are used to test whether a value or variable is in a sequence.

in True if value is found in the sequence
not in True if value is not found in the sequence

 

 

conditional operators:

re used to execute certain blocks of code based on specific conditions. These statements help control the flow of a program, making it behave differently in different situations.

allow Computer to execute a certain canal only if it is true

 

·    if Statement:

is the simplest form of a conditional statement. It executes a block of code if the given condition is true.

 If – else:

alows us to specify a block of code that will execute if the condition(s) associated with an if or elif statement evaluates to False. Else block provides a way to handle all other cases that don't meet the specified conditions.

 

Short hand if

Short-hand if statement allows us to write a single-line if statement.

 

Short Hand if -else

 

The short-hand if-else statement allows us to write a single-line if-else statement.

 

Elif statement

 stands for "else if." It allows us to check multiple conditions , providing a way to execute different blocks of code based on which condition is true. Using elif statements makes our code more readable and efficient by eliminating the need for multiple nested if statements.

 

 Loop in python

are used to repeat actions efficiently.

The main types are For loops (counting through items) and While loops (based on conditions). Additionally,

, Nested Loops allow looping within loops for more complex tasks.

While loop

 is used to execute a block of statements repeatedly until a given condition is satisfied. When the condition becomes false, the line immediately after the loop in the program is executed.

Else clause is only executed when our while condition becomes false. If we break out of the loop or if an exception is raised then it won’t be executed. 

 

 

For loop

are used for sequential traversal. For example: traversing a list string or array  etc. In Python, there is “for in” loop which is similar to for each loop in other languages. Let us learn how to use for loops in Python for sequential traversals with examples.

 While true:

It is a infinite loop

 To break while loop break Statement are used

 

Nested loop

A loop inside a loop

Nested loop are also used to solve patten problem

 

 

 

For loop in conditional Statement

The use of if else statement  increase the ability of a for loop to computer a task efficiently by use if else statement we can provide with special condition inside for loop

 

 

Block & continue :

Continue Statement :

 Is used to when you want to skip a particular condition

Break

Used when you want to display a loop a certain condition

 

 

 

 String manipulation:

Is a combination of number Symbol & latter enclose inside question

Creation of an String:

String are created by enclose number latter symbol inside doble question

A = “hello world”

Print(A)

Print(type(A))

 

·      A = “hello”

·      Print(Len(A))

·      Print(A. count(“h”))

·      Print(A.upper())

·      Print(A.lower())

·      Print(a.index())

·      Print(A.capatalize())

·      Print(a.find())

 

 

String function

§  Isalphanum

§  Isalpha

§  Isdecimal

§  Isdegit

§  Islower

§  End switch

§  Swap case

§  Strip

§  Split

§  Ljust

§  R just

§  Replace

§  Rindex

 

 

 

List: is a collection of order & Mutable data list and written inside the Seqared bracket  the value inside  list is separated by comma mutable means one created they can be changed

Mutable datatype can be written inside list

 

A =[1,2,3,4,5,6,7,8,9]

Print ((2))

Print(a[1:6])

Print(a[:6])

Print(a[1:])

Print(a[:::2])

Print(a[-3:-1])

Print(a[:: -1])

Print(a[-1:-5])

 

 

 

 

 

 

 

Iteration

An iterator in Python is an object that holds a sequence of values and provide sequential traversal through a collection of items such as lists, tuples and dictionaries. . The Python iterators object is initialized using the iter() method. It uses the next() method for

 iteration.

1.    __iter__(): __iter__() method initializes and returns the iterator object itself.

2.    __next__(): the __next__() method retrieves the next available item, throwing a StopIteration exception when no more items are available.

Difference between Iterator and Iterable

Iterables are objects that can return an iterator. These include built-in data structures like lists, dictionaries, and sets. Essentially, an iterable is anything you can loop over using a for loop. An iterable implements the __iter__() method, which is expected to return an iterator object.

Iterators are the objects that actually perform the iteration. They implement two methods: __iter__() and __next__(). The __iter__() method returns the iterator object itself, making iterators iterable as well.

 

Creating an iterator

Creating a custom iterator in Python involves defining a class that implements the __iter__() and __next__() methods according to the Python iterator protocol.

·        Define the Class: Start by defining a class that will act as the iterator.

·        Initialize Attributes: In the __init__() method of the class, initialize any required attributes that will be used throughout the iteration process.

·        Implement __iter__(): This method should return the iterator object itself. This is usually as simple as returning self.

·        Implement __next__(): This method should provide the next item in the sequence each time it’s called.

 

For loop :

A =[1,2,3,4,5,6,7.8]

For I in a:

Print(i)

For I in range(len(a))

Print(a[i])

 

 

While loop :

I =0

While (i<length(a)

Print(a[i])

I+=1

 

Short hand for loop :

(print(p) for I in a )

 

Function:

A =[1,2,3,4,5,6,7,8]

Print(a)

Print(len(a))

Print(a.count(5))

a.apppand(9))

print(a)

a.insert[10,7]

print(a)

a.reverse(5)

print(a)

 

copy

access

extend

Short

Clear

reverse

 

  
Tuple :

Are the collection of order & unmeetable data

For tuple no bracket are  mandatory But choose we can use parentheses

The value inside tuple is separated by comma

One created tuple cannot be changed

Multiple datatype can be written inside a tuple

 slicing is a technique to extract a sub-part of a tuple. It uses a range of indices to create a new tuple from the original tuple.

 

 

 

Multiple assignment using a Python tuple

You’ve seen something called tuple unpacking in the previous topic. There’s another way to unpack a tuple, called multiple assignment. It’s something that you see used a lot, especially when returning data from a function, so it’s worth taking a look at this.

 

Indexed access

We can access a tuple using index numbers like [0] and [1]:

 

Append to a Python Tuple

Because a tuple is immutable, you can not append data to a tuple after creating it. For the same reason, you can’t remove data from a tuple either. You can, of course, create a new tuple from the old one and append the extra item(s) to it this way:

 

Get tuple length

The len() function works on Python tuples just like it works on all other iterable types like lists and strings:

 

Python Tuple vs List

The most significant difference between a Python tuple and a Python list is that a List is mutable, while a tuple is not. After defining a tuple, you can not add or remove values. In contrast, a list allows you to add or remove values at will. This property can be an advantage; you can see it as write protection. If a piece of data is not meant to change, using a tuple can prevent errors. After all, six months from now, you might have forgotten that you should not change the data. Using a tuple prevents mistakes.

 

Dictionaries in Python

 

s a data structure that stores the value in key: value pairs. Values in a dictionary can be of any data type and can be duplicated, whereas keys can’t be repeated and must be immutable.
Example: Here, The data is stored in key:value pairs in dictionaries, which makes it easier to find values.

 dictionary can be created by placing a sequence of elements within curly {} braces, separated by a ‘comma’.

·        From Python 3.7 Version onward, Python dictionary are Ordered.

·        Dictionary keys are case sensitive: the same name but different cases of Key will be treated distinctly.

·        Keys must be immutable: This means keys can be strings, numbers, or tuples but not lists.

·        Keys must be unique: Duplicate keys are not allowed and any duplicate key will overwrite the previous value.