Python Variables
Variables are employed to keep data values. Python is a dynamically typed language, so you don't need to declare a variable type explicitly.
Example:
name
=
"john"
#type str
age
=
22
#type int
Variable Names
- Variable name should begin with a letter or the underscore character
- Variable name shall consist only of alpha-numeric characters and underscore (A-z, 0-9, and _).
- Variables are case sensitive.
- The variable name must not begin with a number.
Example:
Fruit
=
"banana"
#valid variable name
FrUit
=
"apple"
#valid variable name
_fruit
=
"mango"
#valid variable name
5fruit
=
"lemon"
#invalid variable name
$fruit
=
"grape"
#invalid variable name
A multi-word variable name can be cumbersome to the reader. To enhance readability, the programmer can follow these:
Example:
NameOfCountry
=
"India"
#Pascal case
nameOfCountry
=
"Japan"
#Camel case
name_of_country
=
"Russia"
#snake case
Global and Local Variables
Variables are classified into two categories: global variables and local variables.
Local Variable
A local variable is declared within a function and can only be accessed from within that function.
Example:
def
my_func():
fruit
=
"Orange"
print(fruit +
" is a local variable.")
my_func()
Output
Orange is a local variable.
Global Variable
Global variables are defined outside of a function and may be used anywhere within the program.
Example:
fruit =
"Orange"
def
my_func():
print(fruit +
" is a global variable.")
my_func()
Output
Orange is a global variable.