Writing Simple Programs

Name: Writing Simple Programs
Author: John Crabtree

Learn key elements and terminology for basic programming in Python

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Course: On-Demand

Computer programmers use variables to keep track of information. This is done by using the assignment statement. Now syntactically, this process is largely the same in most languages. You have a variable on the left and the information on the right, but the proper way to think about what actually happens under the covers differ slightly depending on the language you're talking about. Now in some languages, like C, you should think of the variable as being a box into which you place a value. That is not the way you should think about Python. Instead, you should think of the variable as some kind of name that you are associating with an object because Python is an object-oriented language. So when you have a variable, you should think of it as being bound to some particular object. Now, in some Python books, you may read phrases like putting values into variables or variables holding values, and that's fine, but one of the best ways to think about this, just think about the variable as being some kind of label or sticky note, and when you're actually binding or sticking a label onto an object. Now be aware that this is not like algebra. In algebra, you can say X equal three or three equal X, and that means the same thing. That is not gonna work in programming. Because with programming, you always have to have the variable on the left and you can't have more than one variable. It's perfectly fine in algebra to say X plus Y equals seven, but the equal sign does not mean the same thing as it does in math. Like I mentioned, the equal sign means assignment. So when you say X equal three, you are binding the sticky to an object, an integer object with a value three, or you can apply a sticky note to the string object, hello. And you can change your mind. You can decide I don't want X to be labeling three, instead I want X to label the string bye. And you can change Y to be associated with a floating point number. Now also be aware that two variables can actually point to or label the same object in memory. So I can say X is going to be bound to two and Y is going to be bound to the same object. So the bottom line is keep in mind that in Python, when you do assignment, you are assigning a name or sticky note to some kind of object in memory.

Beginner Provider : John Crabtree 4 Lessons · 16m in Arabic, German, English, Spanish, French, Portuguese, Chinese

Course Description

The use of variables in the process of assignment is discussed and demonstrated. The rules for naming variables and other identifiers is covered along with the dynamic nature of assigning names to Python objects. Finally, operations, expressions, and statements are defined and several examples are provided and explained.

LEARNING OBJECTIVES:

What You'll Learn

Understand how variable assignment in Python defines or labels objects
Apply the rules for naming variables and other identifiers
Recognize that identifiers name variables, functions, and classes, and are styled differently across programming languages
Assign names to Python objects and work with the dynamic nature of assignment
Define and use expressions, statements, and operations as the building blocks of programming

Key Takeaways

In Python, variable assignment defines or labels objects rather than storing values in fixed containers.
Identifiers are the names applied to variables, functions, and classes, and they are styled differently across programming languages.
Names can be dynamically assigned to Python objects.
Expressions, statements, and operations are the building blocks of programming.

Frequently Asked Questions

What does this course cover?

It covers the use of variables in assignment, the rules for naming variables and other identifiers, the dynamic nature of assigning names to Python objects, and the definition of operations, expressions, and statements with worked examples.

What lessons are included in this course?

The course includes four lessons: Variables and Assignments; Identifiers; Objects; and Expressions, Statements, and Operations.

What skills does this course help build?

It relates to Computer Programming, Programming Concepts, Programming Language Design, Programming Tools, Python (Programming Language), and Shared Variables.

How does the course teach these concepts?

Concepts such as variable assignment are discussed and demonstrated, and several examples of operations, expressions, and statements are provided and explained.