THE PYTHON VARIABLES, DATA TYPES & KEYWORDS

Python Variables, Data Types & Keywords
Now we are getting used to Python and its way, we think it is time to sharpen Python Variables, Datatypes, and Keywords in our brains. First, let's start with Python variables. Here we go...

Python Variables:
A Python Variable is a reserved memory location to store values. In other words, a variable in a Python program gives data to the computer for processing. Python variable is also known as an identifier and used to hold value.
Now, while declaring variables, we need to keep certain things in mind. Before we understand that things in mind, look at this, How we can declare variables in Python Programming Language.

Rules of declaring Variables in Python:

• A variable name start with a letter or an underscore character.
• A variable name cannot start with numbers.
• A variable name can only contain alpha-numeric character and underscore(A-z, 0-9, _)
• Variable names are case-sensitive (techie, Techie, TECHIE are different variables)

Remember that variable's name are case-sensitive.

#Legal Variable Name

var="Techiemania"

_var="Techiemania"

VAR="Techiemania"

var1="Techiemania"

#Illegal Variable Name

2var="techiemania"

my  var="Techiemania"

my - var="Techiemania"

Assign the value to multiple Variables

Code:

x,y = "Techie", "Mania"

print(x)

print(y)

Output:

Techie 

Mania

And you can assign the same value to multiple variables in one line:

Code:

x = y = "Techie Mania"

print(x)

print(y)

Output:

Techie Mania

Techie Mania

Output Variable:
The Python print statement is often used to output Variables
To combine both text and a variable, Python uses the + character

Code:
x = "Mania"
print("Techie" + x)
 Output:
Techie Mania

You can also add the + character to add a variable to another variable.
Code:
x = "Techie"
y = "Mania"
z = x+y
print(z)
Output:
Techie Mania

For numbers, the + character works as mathematical operator
Code:
x = 5
y = 10
print(x+y)
Output:
15

If you try to combine a string and number, Python will give you an error
Code:
x = 5
y = "Techie"
print(x + y)
Output:
Type error: unsupported operand type(s) for +: 'int' and 'string'

Global Variable:
Variables that are created outside of a function are known as Global Variables.
Global Variables can be used by everyone, both inside of a function and outside.

Create a variable outside a function, and use it in inside the function
Code:
x = "Mania"

def myfunc( ):
       print("Techie" + x)

myfunc( )
Output"
Techie Mania

If you create a Variable with the same name inside a function, this variable will be local, and can only be used inside the function. The Global Variable with the same name will remain as it was, global and with the original value.

Create a Variable inside a function, with the same name as the global variable.
Code:
x = "awesome"

def myfunc( ):
     x = "fantastic"
Print("TechieMania is" + x)

myfunc( )
 print("TechieMania is" + x)
Output:
TechieMania is fantastic
ThecieMania is awesome

Python Data types:
In programming, a data type is an important concept.
Variables can store data of different types, and different types can do different things.
Hence, we do not need to define the type of the variable while declaring it.
a = 10
The variable holds integer value ten and we did not define its type. Python interpreters will automatically interpreter variables as an integer type.

Consider the following example to define the values of different data types and checking their type.
Code:
a = 10
b = "TechieMania"
c = 10.5
print(type(a))
print(type(b))
print(type(c))
Output:
<type, 'int'>
<type, 'string'>
<type, 'float'>

Standard data type:
A variable can hold different types of values. For example, a person's name must be stored as string whereas its id must be stored as an integer.
Python provides various standard data types that define the storage method on each of them. The data types defined in python are given below:

1. Numbers
2. Sequence Type
3. Boolean
4. Set
5. Dictionary

Built-in Data types:
Python has the following data types built-in by default, in these categories:

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

Getting the Data Type:
You can get the data type of any object by using the type( )  function:
Code:
x = 10
print(type(x))
Output:
<class, 'int'>

Python Keywords:
Python keywords are special reserved words that convey a  special meaning to the compiler. Each keyword has a special meaning and a specific operation. These keywords can't be used as a variable.
Following is the list of Python keywords:

true	false	none	and	as
asset	def	class	continue	break
else	finally	Elif	del	except
global	for	if	from	import
raise	try	or	return	pass
nonlocal	in	not	is	lambda

Hope this article found you interesting and helpful.
Thank You.

~ Jinal Menpara