Variables are nothing but reserved memory locations to store values. Based on the data type of a variable, the interpreter allocates memory.
Python variables do not
need explicit declaration to reserve memory space. The declaration happens
automatically when you assign a value to a variable. The equal sign (=) is used
to assign values to variables.
Example:
counter = 100 # An integer assignment
miles = 1000.0 # A floating point
name = "John" # A string
Python allows you to
assign a single value to several variables simultaneously.
a = b = c = 1
Multiple objects can be assigned to multiple variables in Python.
a,b,c =
1,2,"Ashraf"
Here, two integer
objects with values 1 and 2 are assigned to variables a and b respectively, and
one string object with the value "Ashraf" is assigned to the variable
c.
Variable Naming Rules
Rules to be followed
for naming variables::
• Python’s key words
cannot be used as a variable name.
• A variable name
cannot contain spaces.
• The first character
must be one of the letters a through z, A through Z, or an underscore
character (_).
• After the first
character you may use the letters a through z or A through Z, the digits 0
through 9, or
underscores.
• Uppercase and
lowercase characters are distinct. This means the variable name ItemsOrdered is
not the same as itemsordered.
A variable in Python
can refer to items of any type. After a variable has been assigned an item of
one type, it can be reassigned an item of a different type.