Variables, Operations and Expressions

Python Tutorials - Herong's Tutorial Examples

∟Variables, Operations and Expressions

This chapter provides introductions and tutorial examples about expressions. Topics include introductions to variables, operations and expressions; operation precedences and execution order.

What Is Variable

What Is Operation

What Is Expression

Conditional Expression - Ternary Operation

Assignment Expression - Walrus Operation

Takeaways:

A variable is a symbolic name of a data object.
A variable can also be considered as an storage for a reference or a pointer to the object.
An operation is a sequence of lexical tokens in Python source code that invokes a predefined action on one or two data objects.
An expression is a sequence of lexical tokens in Python source code that expresses a single object, a single operation, or multiple operations executed sequentially.
Operations enclosed within parentheses are executed first.
Operations with higher precedences are executed first.
Operations on the left are executed first, if they have the same precedence.
An expression always produces an object.