-> Python Basics
-> Python Intermediate
-> Python Advanced
-> Python Production Level
- Understand basics and more advanced concepts in python language.
- Be introduced to data analysis using pandas,numpy and data analysis library.
- walk through the process of interviewing and answering technical questions.
- learn how to build projects on real-world applications with the python language.
- Print statement
- variables
- Operators
- Data types
- Control and Condition statemens
->Print statement is one of the most basic and popular functions in python - the print() statement.
->Python print() function is used to print the specified object to the standard output device (screen) or to a text stream file.
->The Python print() method is used to print a given message to the screen or to display an object’s value on the terminal.
for example: print('Hello World!')
->A variable is a named memory location in which we can store values for the particular program.
->In Python, We don't need to declare explicitly variable in Python. When we assign any value to the variable that variable is declared automatically.
->In Python, We don't need to specify the type of variable because Python is a loosely typed language.
-Rules for naming variable:
->Variable names can be a group of both letters and digits, but they have to begin with a letter or an underscore.
->It is recommended to use lowercase letters for variable name. 'SUM' and 'sum' both are two different variables.
example:
a=12 #interger
b=1.2 #float
c="Hello" #string
->Python allows us to assign a value to multiple variables and multiple values to multiple variables in a single statement which is also known as multiple assignment.
Assign single value to multiple variables:
example: a=b=c=10
Assign multiple values to multiple variables:
example: a,b,c=1,2,3
->Operators in Python are special symbols that carry arithmetic or logical operations. The value that the operator operates on is called the operand.
->In python there are 7 different types of Operators:
+ (addition)
- (subtraction)
*(multiplication)
/(divide)
%(reminder)
// (floor division)
** (exponent)
in (True, If the value is present in the data structure)
not in (True, If the value is not present in the data
structure)
== (Equal to)
!= (Not equal to)
<= (Less than or equal)
>= (Greater than or equal)
< (Less than)
> (Greater than)
= (Assigns to)
+= (Assignment after Addition)
-= (Assignment after Subtraction)
*= (Assignment after Multiplication)
/= (Assignment after Division)
%= (Assignment after Modulus)
**= (Assignment after Exponent)
//= (Assignment after floor division)
& (binary and)
| (binary or)
^ (binary xor)
~ (negation)
<< (left shift)
>> (right shift)
and (logical and)
or (logical or)
not (logical not)
is (Returns true if both variables are the same object)
is not (Returns true if both variables are not the same object)
->In general, data types specifies what type of data will be in variables
->Python provides following standard data types:
1.Numbers
2.Strings
3.Lists
4.Tuple
5.Set
6.Dictionaries
7.Boolean
8.None
->Numbers store numeric values
->There are 3 numeric types in python
1.int:It is a whole number,positive and negative
without decimals.
example: a=7,b=-11,c=-23
2.float:It is a floating number,positive or negative
with containing one or more decimals.
example: p=2.12,q=16.0,r=-4.6
3.complex:Complex numbers are written with a"j" as the
imaginary part.
example: a=3+5j,b=-4+9j,c=-27j
->The string can be defined as a sequence of characters represented in quotation marks.
example: s1='Hi', s2="Hello", s3="'world'"
->Python strings are immutable which means they cannot be changed after they are created.
-> indexing in strings starts from 0.And in negetive indexing -1 refers to last item,-2 is 2nd last element and so on.
->String build-in functions are used for string handling.
->A list is a collection of items that are orderd and mutable.Lists are represented with square bracket and items are separated by commas.
example: list=[2,3,4,7], list2=[2.4,1.1,30.0]
->Indexing in list is as same as in python strings.
->Python list build-in functions are used for adding,deleting,updating of items in the list.
->A tuple is a sequence of immutable element or items and it can store multipleitems in a single variable.
->A tuple can be represented in small brackets().
->Indexing in tuple is as same as in python strings and lists.
->There are only two build-in functions in a tuple for accessing the items 1.count 2.index.
example: t1=(1,'python',4.2) , t2=('c',)
->A set is a unordered collectionof items.Every elementis unique and must be immutable.And are represented by curly braces {}.
->Set doesnot have indexing because set is unordered.
->However,the set itself is mutable.We can add or remove items from it.
->Sets are used to perform mathematical set operations like union,intersection etc.
->Set elements can be of different types,like list,tuple,set or dictionary
example: s1={1,2,3}, s2={[1,23,45]},
s3={1.0,'Python',[24,11,2.0]}
->A dictionary is a unorderd collection of key-value pairs.Dictionaries are represented by curly braces {}, key and values are separated by colons ','.
->Dictionary is mutable and Dictionaries are indexed by keys.
example: {"name":"jayanth","age":21}
->Boolean data type generally has only two values 'True' or 'False'.
example: input: 24==24
output: True
input: 11<7
output:False
->Python uses the keyword None to define null objects and variables.
example: input: a=None
print(a)
output: None
-> Conditional statements
-> Loop statements
-> control statements
-> Functions
-> lambda functions
-> Comprehensions
-> Recursion
-> JSON
-> Conditional statements perform different actions and computations based on conditions.
-> In python there are 3 Conditional statements:
1. if
2. if-else
3. if-elif-else
-> An if statement is used to check a condition,and execute it if the condition holds true.
Syntax:
if condition:
statement 1
statement 2..
example:
if 2>1:
print('True')
-> An if-else statement is used to execute both true part and false part in the given condition.
Syntax:
if condition:
statement 1
statement 2..
else:
statement 3
statement 4..
example:
a=2
b=1
if a>b:
print('True')
else:
print('False)
-> we can use if-elif-else statement to tell python to try a different condition if the previous conditions were not met.
Syntax:
if condition 1:
statement 1
statement 2..
elif condition 2:
statement 3
statement 4..
elif condition 3:
statement 5
statement 6..
else:
statement 7
statement 8..
example:
a=1
b=2
c=3
if a>b:
print('a is Greater than b')
elif b>c:
print('b is Greater than c')
elif c>a:
print('c is Greater than a')
else:
print('all are same')
-> Looping means repeating something over and over until a particular condition is satisfied.
Types of Loops
1. While Loop
2. For Loop
3. Nested Loop
-> A while loop allows code to be executed repeatedly,depending on whether a condition is satisfied or not.
Syntax:
while condition:
statement(s)
example:
i=1
while i<=2:
print(i)
i=i+1
output:
1
2
-> The for loop in python is used to iterate the statements or a part of program several times.It is frequently used to traverse the data structures like list,tuple,string or dictionary.
Syntax:
for iterating_var in sequence:
statement(s)
example:
for i in range(1,4):
print(i)
output:
1
2
3
-> A nested loop refers to a loop within a loop,an inner loop within the body of an outer one.
example:
for i in range(5):
for j in range(5):
print('*',end=' ')
print()
output:
* * * * *
* * * * *
* * * * *
* * * * *
* * * * *
-> control statements in python are used to alter the flow of a loop like you want to skip a part of a loop or terminate a loop.
->In python, the following are jump statements.
break
continue
pass
->The break is a keyword in python which is used to bring the program control out of the loop.
example:
n=[10, 40, 120, 230]
for i in n:
if i>100:
break
print('current number',i)
output:
curret number 10
curret number 40
->The continue statement skip the current iteration and move to the next iteration.
example:
for i in range(1,7):
if i==5:
continue
print(i)
output:
1
2
3
4
6
->Do nothing. Ignore the condition in which it occurred and proceed to run the program as usual.
-> Piece of reusable code
-> Solves particular task
-> Call function instead of writing code yourself
syntax:
def fun_name(parameters):
statement(s)
example:
def add(a,b):
sum=a+b
print('sum=',sum)
add(2,3)
->Recursion generally means finding a solution to a problem by repeatedly solving the simpler versions of the same problem.
->In Python, recursion is the process of a function calling itself directly or indirectly. This is a way to get to the solution of a problem by breaking it into smaller and simpler steps.
->The syntax of recursion in Python is:
Syntax:
def func_name(parameters):
func_name(updated parameters)
->JSON is a syntax for storing and exchanging data. JSON is text, written with JavaScript object notation.
->Python has a built-in package called json, which can be used to work with JSON data.
-> File Handling
-> Exception Handling
-> OOP's
->File is a named location on disk to store related information.
->It is used to permanently store data in non-volatile memory.
->read(chars): reads the specified number of characters starting from the current position.
->readline(): reads the characters starting from the current reading position up to a newline character.
->readlines(): reads all lines until the end of file and returns a list object.
Similarly, for writing data to files, we have to use open() with 'wt' mode Also, we have to use the write() function to write into a file.
->Similarly, for writing data to files, we have to use open() with 'wt' mode
->Also, we have to use the write() function to write into a file.
f=open('filename.txt' , 'wt')
f.write ('hi there, this is a first line of file.\n’)
f.write ('and another line.\n’)
f.close()
Output:
hi there, this is a first line of file. and another line.
->With statement is used when we have two related operations which we would like to execute as a pair, with a block of code in between
Example: opening a file, manipulating a file and closing it
with open(“output.txt”,”w”) as f:
f.write(“Hello Python!”)
->The above statement automatically close the file after the nested block of code.
->Encountering errors and exceptions can be very frustrating at times, and can make coding feel like a hopeless endeavor.
->Python Errors can be of three types:
Compile time errors (Syntax errors)
Runtime errors (Exceptions)
Logical errors
->The try block lets you test a block of code for errors. The except block lets you handle the error.
->The finally block lets you execute code, regardless of the result of the try- and except block.
example:
a=int(input(“First Number:”)) b=int(input(“Second number”))
result=a/b
print(“Result=”,result)
except ZeroDivisionError: print(“Division by zero”)
else:
print(“Successful division”)
Output:
First Number:10 Second number:0
Division by zero
->class
->object
->constructor
->self
->Inheritance
->Polymorphisam
->Abstraction
->Encapusulation
->A class is a special data type which defines how to build a certain kind of object.
-> object is the instance of a class.
->constructors are two types
1.Non parameter constructor
2.Parameter constructor
-> non parameter constructortakes no arguments.
-> A parameter constructor takes one or two arguments.
->The first argument of every method is a reference to the current instance of the class.
->It refers to defining a new class with little or no modification to an existing class.
->The new class is called derived (or child) class and the one from which it inherits is called the base (or parent) class. -> There are different types of Inheritance: ->Single Inheritance ->Multilevel Inheritance ->Multiple Inheritance ->HIERARICAL Inheritance ->Hybrid Inheritance
->Basically it is a greek word where poly -> Many Morphisam means -> forms.
->this concept is having 2 internal types
1.Method Overloading->
2.Method Overriding
->It refers to a programming approach by which only the relevant data about an object is exposed, hiding all the other details.
->The terms encapsulation and abstraction (also data hiding) are often used as synonyms. They are nearly synonymous.
->Generally speaking encapsulation is the mechanism for restricting the access to some of an objects's components, this means, that the internal representation of an object can't be seen from outside of the objects definition.
->There 3 types of data in Encapusulation
1.public
2.private
3.protected
1.Multiprocessing
2.MultiThreading
->A process is a sequence of instructions executed in a predefined order.
->A multiprocessing is a act of running many processes simultaneously.
-> MultiThreading is the ability of a processor to execute multiple threads concurrently.
->It enables more than one user at a time without requiring multiple copies of the program running on the computer.