How to master python language?

Python :-

Python has become one of the fastest growing and most popular programming languages in the world. Is it a good choice for your next project though? Python is versatile, it is easy to use and develop.
The python language is one of the most accessible programming languages available because it has simplified syntax and not complicated, which gives more emphasis on natural language. Due to its ease of learning and usage, python codes can be easily written and executed much faster than other programming languages.

Python so Popular Because :

1.Easy to Learn and Use
2.Efficiency, Reliability, and Speed
3.Hundreds of Python Libraries and Frameworks
4.The Flexibility of Python Language
5.Use of python in academics

What is Python?

Python is a popular programming language. It was created by Guido van Rossum, and released in 1991
It is used for:
1.web development (server-side),
2.software development,
3.mathematics,
4.system scripting.

What can Python do?

1.Python can be used on a server to create web applications.
2.Python can be used alongside software to create workflows.
3.Python can connect to database systems. It can also read and modify files.
4.Python can be used to handle big data and perform complex mathematics.
5.Python can be used for rapid prototyping, or for production-ready software development.

Why Python?

1.Python works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc).
2.Python has a simple syntax similar to the English language.
3.Python has syntax that allows developers to write programs with fewer lines than some other programming languages.
4.Python runs on an interpreter system, meaning that code can be executed as soon as it is written. This means that prototyping can be very quick.
5.Python can be treated in a procedural way, an object-oriented way or a functional way.

Python Syntax compared to other programming languages:-

1.Python was designed for readability, and has some similarities to the English language with influence from mathematics.
2.Python uses new lines to complete a command, as opposed to other programming languages which often use semicolons or parentheses.
3.Python relies on indentation, using whitespace, to define scope; such as the scope of loops, functions and classes. Other programming languages often use curly-brackets for this purpose.
Example
print("Hello, World!")

Python Variables:-

Variables are containers for storing data values.

1.Creating Variables

• Python has no command for declaring a variable.
• A variable is created the moment you first assign a value to it.

Example
x = 5
y = "John"
print(x)
print(y)

Variables do not need to be declared with any particular type, and can even change type after they have been set.

Example
x = 4 # x is of type int
x = "Sally" # x is now of type str
print(x)

2.Casting
If you want to specify the data type of a variable, this can be done with casting.

Example
x = str(3) # x will be '3'
y = int(3) # y will be 3
z = float(3) # z will be 3.0

3.Get the Type
You can get the data type of a variable with the type() function.

Example
x = 5
y = "John"
print(type(x))
print(type(y))

4.Single or Double ?
String variables can be declared either by using single or double quotes:

Example
x = "John"
# is the same as
x = 'John'

5.Case-Sensitive
Variable names are case-sensitive.

Example
This will create two variables:
a = 4
A = "Sally"
#A will not overwrite a

Python Data Types:-

1-Built-in Data Types-
• In programming, data type is an important concept.
• Variables can store data of different types, and different types can do different things.
• Python has the following data types built-in by default, in these categories:

Text Type: str
Numeric Types: int, float, complex
Sequence Types: list, tuple, range
Mapping Type: dict
Set Types: set, frozenset
Boolean Type: bool
Binary Types : bytes, bytearray, memoryview

2-Getting the Data Type-
You can get the data type of any object by using the type() function:

Example
Print the data type of the variable x
x = 5
print(type(x))

Python Lists:-

Lists
• Lists are used to store multiple items in a single variable.
• Lists are one of 4 built-in data types in Python used to store collections of data, the other 3 are Tuple, Set, and Dictionary, all with different qualities and usage.
• Lists are created using square brackets:

Example
Create a List:
thislist = ["apple", "banana", "cherry"]
print(thislist)

List Items:-
• List items are ordered, changeable, and allow duplicate values.
• List items are indexed, the first item has index [0], the second item has index [1] etc.

Ordered:-
• When we say that lists are ordered, it means that the items have a defined order, and that order will not change.
• If you add new items to a list, the new items will be placed at the end of the list.
Note: There are some list methods that will change the order, but in general: the order of the items will not change.

Changeable:-
The list is changeable, meaning that we can change, add, and remove items in a list after it has been created.

Allow Duplicates:-
Since lists are indexed, lists can have items with the same value:

Example
Lists allow duplicate values:
thislist = ["apple", "banana", "cherry", "apple", "cherry"]
print(thislist)

List Length:-
To determine how many items a list has, use the len() function:

Example
Print the number of items in the list:
thislist = ["apple", "banana", "cherry"]
print(len(thislist))

Python Dictionaries:-

Dictionary
• Dictionaries are used to store data values in key:value pairs.
• A dictionary is a collection which is ordered*, changeable and does not allow duplicates.
• As of Python version 3.7, dictionaries are ordered. In Python 3.6 and earlier, dictionaries are unordered.
• Dictionaries are written with curly brackets, and have keys and values:

Example
Create and print a dictionary:

thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
print(thisdict)

Dictionary Items:-
• Dictionary items are ordered, changeable, and does not allow duplicates.
• Dictionary items are presented in key:value pairs, and can be referred to by using the key name.
Example
Print the "brand" value of the dictionary:
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
print(thisdict["brand"])

Ordered or Unordered?:-
• As of Python version 3.7, dictionaries are ordered. In Python 3.6 and earlier, dictionaries are unordered.
• When we say that dictionaries are ordered, it means that the items have a defined order, and that order will not change.
• Unordered means that the items does not have a defined order, you cannot refer to an item by using an index.

Changeable:-
Dictionaries are changeable, meaning that we can change, add or remove items after the dictionary has been created.

Duplicates Not Allowed:-
Dictionaries cannot have two items with the same key:

Example
Duplicate values will overwrite existing values:
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964,
"year": 2020
}
print(thisdict)

Dictionary Length:-
To determine how many items a dictionary has, use the len() function:

Example
Print the number of items in the dictionary:
print(len(thisdict))

Python Loops:-

Python has two primitive loop commands:
1.while loops
2.for loops

Python While Loops
• With the while loop we can execute a set of statements as long as a condition is true.

Example
Print i as long as i is less than 6:
i = 1
while i < 6:
print(i)
i += 1
Note: remember to increment i, or else the loop will continue forever.
• The while loop requires relevant variables to be ready, in this example we need to define an indexing variable, i, which we set to 1.

The break Statement:-
With the break statement we can stop the loop even if the while condition is true:

Example
Exit the loop when i is 3:
i = 1
while i < 6:
print(i)
if i == 3:
break
i += 1

The continue Statement:-
With the continue statement we can stop the current iteration, and continue with the next:

Example
Continue to the next iteration if i is 3:
i = 0
while i < 6:
i += 1
if i == 3:
continue
print(i)

The else Statement:-
With the else statement we can run a block of code once when the condition no longer is true:

Example
Print a message once the condition is false:
i = 1
while i < 6:
print(i)
i += 1
else:
print("i is no longer less than 6")

Python For Loops
• A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string).
• This is less like the for keyword in other programming languages, and works more like an iterator method as found in other object-orientated programming languages.
• With the for loop we can execute a set of statements, once for each item in a list, tuple, set etc.

Example
Print each fruit in a fruit list:
fruits = ["apple", "banana", "cherry"]
for x in fruits:
print(x)
The for loop does not require an indexing variable to set beforehand.

Looping Through a String
Even strings are iterable objects, they contain a sequence of characters:

Example
Loop through the letters in the word "banana":
for x in "banana":
print(x)

The break Statement:-
With the break statement we can stop the loop before it has looped through all the items:

Example
Exit the loop when x is "banana":
fruits = ["apple", "banana", "cherry"]
for x in fruits:
print(x)
if x == "banana":
break

The continue Statement:-
With the continue statement we can stop the current iteration of the loop, and continue with the next:

Example
Do not print banana:
fruits = ["apple", "banana", "cherry"]
for x in fruits:
if x == "banana":
continue
print(x)

Else in For Loop
The else keyword in a for loop specifies a block of code to be executed when the loop is finished:

Example
Print all numbers from 0 to 5, and print a message when the loop has ended:

for x in range(6):
print(x)
else:
print("Finally finished!")
Note: The else block will NOT be executed if the loop is stopped by a break statement.

Example
Break the loop when x is 3, and see what happens with the else block:

for x in range(6):
if x == 3: break
print(x)
else:
print("Finally finished!")

Nested Loops
A nested loop is a loop inside a loop.
The "inner loop" will be executed one time for each iteration of the "outer loop":

Example
Print each adjective for every fruit:

adj = ["red", "big", "tasty"]
fruits = ["apple", "banana", "cherry"]
for x in adj:
for y in fruits:
print(x, y)

Python Functions:-

A function is a block of code which only runs when it is called.

You can pass data, known as parameters, into a function.
A function can return data as a result.

Creating a Function:-
In Python a function is defined using the def keyword:

Example
def my_function():
print("Hello from a function")

Calling a Function:-
To call a function, use the function name followed by parenthesis:

Example
def my_function():
print("Hello from a function")
my_function()

Conclusion :

Python is a fully-fledged programming language. Any code you download from github, the Python Package Index, or anywhere else, can be malicious and would almost certainly go unnoticed by most people's firewalls.We hope this article has shed some good light on python language and its importance. So if anyone asks you “what is python programming?” you have an essay answer ready.