A Short notes on Python Programming
Computer Memory
For the purpose of this course,
you may think of computer
memory as a long list of
storage locations where each location is identified with a unique number and
each location houses a value. This unique number is called a memory address. Typically, we
will write memory addresses as a number with an "x" as a prefix to
distinguish them from other numbers (for example,x201
is memory address 201).
Variables are a way to keep track of values stored in computer memory. A variable is a named location in computer memory. Python keeps variables in a separate list from values. A variable will store a memory address, and it is that memory address that stores the value. The variable then refers to the value. Python will pick the memory addresses for you.
Terminology
A value has a memory address.
A variable stores a memory address.
A variable refers to a value.
A variable points to a value.
Example: Value 8.5
has memory address x34
.
Variable shoe_size
stores memory address x34
.
The value of shoe_size
is 8.5
.
shoe_size
refers to value 8.5
.
shoe_size
points to value 8.5
.