Tag Archives: teach programming

Python Debugging Strategies for Beginners

Explicitly teaching Python debugging strategies provides students with a toolkit of techniques. The same debugging strategy cannot be applied to every problem. Provide students with a multitude of strategies and explain when they are most effective. This will enable programmers to thoughtfully debug their programs using a toolkit full of techniques.

10 Python Debugging Strategies for Beginners

Do not wait until the end of a programming unit to teach Python debugging strategies. Instead, help students find and fix bugs. Below are 10 techniques that will build confidence and independence in your students. They are based on using IDLE Python to write code. Many of these strategies are included in the Python project TechnoTurtle for elementary and middle school students.

1. Look Before Highlighted Word to Find Syntax Errors

Syntax is the set of rules for how to order words and use symbols to write code. If a bracket, colon, or indentation is missing the IDLE Python program will show a Syntax Error box on the screen to identify the problem. It will also highlight a word to pinpoint the location.

Do not be fooled! The problem is not the highlighted word. Instead the mistake is BEFORE it. Look at the words just in front of the highlighting, or the line of code above to find the error.

Syntax errors are often typos. Missing commas, hashtags, or too many brackets are common. If that isn’t the issue, study the order of the words as they might be put together wrong.

Explicitly teaching Python debugging strategies. A Syntax Error is often missing symbols such as a colon, comma, or hashtag. Tell young programmers to look before the highlighted word.

2. Indent a Block of Instructions the Same Number of Spaces

Instructions that loop or run when a condition is met, are grouped together by indenting the lines of code to form a block. For example:

# correct way to make a loop
if answer==”tiger”:
print(“You are right.”)
print(“You win!”)

# wrong way to make a loop
if answer==”tiger”:
print(“You are right.”)
print(“You win!”)

When the code is not written correctly, IDLE Python will show a Syntax Error that states, “expected an indented block”. When this happens, check to see if the first line ends with a colon. If it does, then verify that each instruction in the block indents the same number of spaces.

3. Skim and Scan the Error Message to Find Clues

IDLE Python will display an error message in the Python Shell. It is in red text. To a novice, it can seem like gibberish. The best thing to do, is to scan the text for familiar words. Look for the line number. This will tell you where the error happened. To quickly go there within the program, right click the line number and select Go to file/line.

Before you view the line of code, study the bottom of the error message for more clues. It may say NameError at the bottom. If it does notice if the word is spelled correctly. If it is then check to see if a library was not imported or a variable was not defined properly.

Scan the message for clues. Look for the line number. Go to the last line to see if a function is spelled wrong. If it is right, you may have forgotten to import a library.

4. Look at the Color Coding

IDLE Python applies a color theme to text. This makes types of Python words different colors. This can be helpful when trying to find mistakes. Here are some helpful Python debugging strategies for beginners:

Comments are red. If a comment is not red, it is likely missing a # at the beginning, such as #this is a comment.
Strings are green. If a string is not green, it is likely missing quotes around it. Or, if a bracket is green, it likely that the end quote is missing.

Use color coding as a clue to find and fix errors.

5. Apply Trial and Error

A proven Python debugging strategy is Trial and Error. Trial and Error is a method of testing different ideas until one is found that works the best. The programmer will run their program and then study the output. They will notice the things that are wrong or unexpected. This analysis allows them to come up with a better idea to try next.

Trial and Error is systematic. The programmer only tries one idea at a time. This way they can pinpoint what is most effective.

Trial and Error is best applied when a programmer is fine-tuning the output. Their code has no syntax or naming errors. Instead, the focus is on discovering the ideal value or sequence of instructions to achieve the goal.

6. Code One Line at a Time

This Python debugging strategy can be used while writing a program or after it is written. When programming, type a line of code at a time and then run the program to test it. This allows you to quickly identify if there are typing errors or an issue with the sequence of instructions. This makes mistakes easier to spot.

Once a program is written, if you cannot find the mistake, divide the code into parts. Copy a chunk at a time into a new program. Run it to see it that section is error free. If it is, add another chunk of code to the program. Continue until you find where things are broken. Now you can focus your attention on that area.

7. Compare Using a Similar Model

If you cannot figure out what is wrong with the code and everything seems right, another Python debugging strategy is to find a similar program. Study the code to notice how it is constructed. This can provide a clue as to why the code is not working properly.

8. Copy and Paste from a Working Program

If you cannot debug the code and you are getting desperate, refer back to your previous work. Use existing code that is error-free as a jumping-off point. Copy a snippet of code that does a similar task from an existing program and paste it into the current file. Adjust the values or text to suit your programming objectives.

9. Enlarge the Font Size to Make the Code Easier to Read

When you have been programming for a long time the text can blur together. To make the lines of code sharper you can increase the font size or change the typeface to something that is easier to read. Now typos might be easier to spot. To do this:

From the IDLE Editor Window, select the Options menu.
Select Configure IDLE
Click the Fonts/Tabs.
Pick a font face such as Arial.
Near the bottom pick a size such as 14.
Click OK.
Click the X to close the window.

Increase the font size and change the font to make bugs easier to spot.

10. Ask a Peer for Help

If you cannot find the error ask a friend for help. Often a fresh set of eyes can easily spot the typo in a line of code that has been looked over a hundred times. If the problem is related to the output, explain what you want the code to do. Look at the code together. Describe what is going right, and pinpoint where things start to go wrong. Run the program and study the outcome. Work together to discover a solution.

Python Debugging Strategies Support Learning

Make time to teach Python debugging strategies. Understanding how to code should not be restricted to those with a natural ability. Instead, provide your students with a toolkit of techniques they can use to find and fix errors. This will develop a positive attitude towards programming, build confidence, and promote independence.

Reasons To Explicitly Teach Debugging Strategies in Python

Teach debugging strategies to beginners. This will enhance the learning experience. The instruction should be evident and apparent to the students. Instead of hoping that young programmers will discover techniques, guide them through proven methods to find and fix errors.

Teach debugging strategies to promote independence, build confidence, and spark a life-long interest in programming.

10 Reasons to Teach Debugging Strategies

There are many benefits to deliberately teaching debugging strategies at the start of a programming unit:

1. Improve Comprehension

Teaching debugging strategies to beginners allows them to make sense of the Python programming language. Similar to reading comprehension, explicit strategy instruction, gives student the skills they need understand text. They learn how to decode the meaning of the error messages and apply techniques to correct the code.

2. Promote Independence

Guiding students through exercises where they break and then repair the code, promotes independent practice. During the activity, young programmers receive instant feedback about what makes code work. This allows them to take control of their own learning.

3. Develop a Deeper Understanding of Code

Young kids are always asking “Why?” As they grow older, they may not ask the question aloud as often but they continue to wonder about their world. When they are taught debugging strategies they begin to form connections to why a line of code must be written in a particular way. They understand the purpose for quotes, brackets, indents, and hashtags. Ultimately, this makes them better programmers.

4. Build Confidence

Young programmers can quickly become discouraged when their programs do not run. In the IDLE Python environment mistakes are highlighted in red with boxes that tell you instantly there is an error. This information on the screen is helpful if a learner knows how to apply it to correct the problem. However, if the meaning of the errors are unknown then they look like gibberish. Instead of having students struggle and give up, teach them strategies they can use to find and fix errors. Each success will build confidence.

5. Encourage a Positive Attitude Towards Programming

One of the goals to teaching programming to elementary and middle school students is to spark an interest in STEM. To ignite a passion for coding, the experience should be fun. Glaring at an error message with no idea how to fix the problem is not enjoyable. In fact, if it goes on too long it can make a novice dislike programming. Teaching students about common errors is empowering. They can make their programs run and see the results of their efforts, which is a great feeling.

6. Establish a Toolkit of Programming Techniques

The same debugging strategy cannot be applied to every problem. For example, Trial and Error is a wonderful way to test ideas. However, it can be inefficient when the issue is a loop missing indented instructions. Provide students with a multitude of strategies and explain when they are most effective. This will enable programmers to thoughtfully debug their programs using a toolkit full of techniques.

7. Reshape How Mistakes How Perceived

Children often believe that mistakes are “bad”. They don’t want their work to be imperfect. Teaching debugging strategies allows students to rethink mistakes. They become teaching tools that promote learning. Also, they enforce that not everything is wrong in the program. Instead only one thing is not quite right. The debugging technique of Trial and Error is an excellent way to celebrate mistakes. Students can experiment with different values or move a line of code to discover how it changes the output. The process of testing an idea and then studying the outcome is one way to put a positive spin on errors.

8. Make Programming Accessible to Everyone

Teaching debugging strategies makes programming attainable for everyone in the class. Success is not limited to only those students who have a natural ability. Instead, beginners can make original creations because they understand how to improve their code.

9. Avoid Classroom Management Problems

It is challenging for a teacher to help a class full of students struggling with the errors in their programs. As frustration levels grow, learners can quickly become disengaged. This can result in behavioral issues as they express how they are feeling. By knowing some simple but effective debugging strategies, students build the skills and confidence they need to troubleshoot code independently.

10. Provide a Foundation for Future Learning

Teaching debugging strategies is a great way to promote a life-long interest in programming. By successfully building programs, young programmers will want to make even more. They will be able to transfer their skills to more complicated programming tasks. Getting over the obstacles to learning at the start of a coding unit invites the possibility that students will continue to code in the future.

Python Lessons for Beginners

TechnoTurtle has programming activities that use explicit strategy instruction to teach debugging strategies. Students are guided through editing Python scripts to find and fix common errors. This provides a foundation for creating their own unique programs.

To learn more about TechnoTurtle, visit TechnoKids.

Python Variables and Offline Coding Exercise

Young programmers need to understand the purpose of Python variables. In a program, variables store values that can change. They are very powerful. They can be used to count, create lists, store user input, report information, personalize the user experience, trigger an action, calculate amounts, and more!

One of the best ways to learn about computer science concepts is hands-on learning. In other words, writing programs that use variables. Talking about variables will generate a limited understanding. Having said that, before jumping into Python programming, it is worthwhile to begin instruction about variables with an offline coding exercise.

Variables can seem a bit abstract to a child. It is worthwhile to make the concept tangible. A quick activity that connects variables to daily life will help elementary and middle school students to form an understanding of their use.

Have your students apply computational thinking to think about the world around them as a set of variables that store and direct events. This knowledge can then be transferred to programming activities. Refer to the connections below as a way to create an offline coding exercise about Python variables.

The Value of a Variable Changes

Just like the weather, a variable is a value that changes. It could be sunny in the morning and then rainy in the afternoon. What is the weather?

Complete the value of the variable weather. For example: weather="sunny"
weather=" "

A Variable Stores Different Types of Information

A variable can be text, a number, or a list. In the above example, the value stored was a word. However, you can also store numbers as variables. Temperature is a numbered variable that changes. It could be 5°C (41°F) at night and then 15°C (59°F) in the afternoon.

Write the value of the variable temperature. For example: temperature="15"
temperature=" "

The Value of a Variable Can Trigger an Event

The value of a variable can cause an action to occur. For example, if it is hot outside you might wear shorts. Or if it is rainy you might use an umbrella.

Complete the script using weather as the variable. What will you wear?

if weather=="snowy":
what will you wear?

An Event Can Trigger the Value of a Variable to Change

When a program starts, a variable has a specific value. However, an event may occur that changes the value. This event could make a number higher or lower. Or, it could assign a new word to a text variable.

When making a decision you might change your mind depending on what is happening. Programs do the same thing! Pretend you are getting dressed for school. What piece of clothing do you want to wear?

Complete the value of the variable clothing
clothing=" "

The item is in the laundry. What piece of clothing will you wear now?
clothing=" "

A Variable Is Stored in a Numbered Location

The value of a variable is saved in a spot that is like a numbered storage bin. When the program needs the value in the variable it takes it from the bin. The computer knows where to find the value because it has a unique location.

Labeling a location to store things is done everyday at school. For example, your school locker may have a number. Or the library may have a numbered bin of books.

Look around your classroom. What bins are used to store things? Are they labelled?

Write your discovery as a variable. For example: mylocker="1215" or period1bin="homework"

bin="item"

A Variable Is an Efficient Way to Refer to Information

A variable is like a container that stores information. The label on the outside is the name. The item you put inside is the value. When giving an instruction, the program uses the variable name, not the data stored in it. This is done to save time and keep things simple.

Imagine it is recess time. The teacher needs to tell the students what to do. The teacher gives the instruction, “Please go and get your snack”. The teacher does not say, “Please go and get your apple, crackers, cookies, carrots, chips, or banana.”

The word “snack” is used to refer to many values. It also allows the values to be unknown. The teacher cannot know what you or your classmates brought for a snack. Using one word that is meaningful is an efficient way to refer to information.

People often use one word to quickly refer to many things. Turn the word lunch into a variable. What is in your lunch today? Make a list of the values in your lunch. For example:

lunch=("orange juice", "ham sandwich", "apple", "blueberry muffin")

lunch=

A Variable Can Store User Information

Sometimes the programmer assigns the value of a variable. Other times, the user inputs a value. This can be done by prompting the user to enter data by displaying a text box or question on the screen. The program can then use this information to sign into an account, customize the settings of an app, or pick a selection.

Think about a game you play on a device. What information does it ask you to input? Each of the pieces of information is a variable.

List two pieces of information you must enter into a game before you could play it. For example:

playername="technokid"

playermode="single player"

Python Variables and Fun Programming Activities for Kids

If you are looking for some fun programming activities for kids that use variables, take a look at TechnoTurtle. This STEM project introduces beginners to Python variables in a way that is easy to understand. Students develop programs that have players play Mad Libs, a Carnival Game, and a Guess the Number Game. Each uses variables to trigger action. These coding activities are a great way to make Python variables meaningful to kids. The lessons provide a foundation for further learning.

Teach children about Python variables using the STEM project TechnoTurtle.

Variables in Python and Teaching Coding to Kids

Variables in Python are used by programmers to store values. These values complete a task within a program. In game design variables can track scores, count the number of turns, or store player answers. However, they have many other uses. When teaching coding to kids, it is important that the purpose of a variable is understood.

Variables in Python store values that a program uses to complete a task.

What Are Variables in Python?

A variable stores a value that can change. It is saved in a special spot that is like a numbered storage bin. When the program needs the value in the variable it takes it from the bin.

A variable can store lots of different types of information. For example, the value could be a number, text, or a list of items. In programming, a number is called an integer or int for short. Text is called a string or str for short.

A variable has two parts – name and value. To create a variable, you write the variable name, then an = symbol, followed by the variable value. For example: player=”Alex”

A variable has two parts – name and value.

Variables in Python Must Have Meaningful Names

Naming a variable is a fundamental skill. A programmer should be able to read the variable name and understand its use within the program. It is very important that it is short but concise. It’s name should describe its purpose.

A Python variable must:

be meaningful
be one word
have no spaces
use no symbols
not be a reserved Python word

Why Use a Variable?

Variables make a program flexible. Programmers use them for many reasons.

Variables Can Count the Number of Times an Event Occurs

Variables can count. This is useful when making a timer or tracking a player’s score. To count, you can create a variable called count=0. Each time the line of code count=count+1 is run than the value of the variable goes up by one.

Variables Can Store Multiple Values as a List

Variables can store more than one value. The list may look like this: pickcolor=(“red”, “blue”, “green”). By assigning multiple values to a variable it allows a program to make a choice. This use of variables creates games that are fun to play because the selection is unknown.

Variables Allow the User to Input Information

Sometimes the programmer assigns the value of a variable. Other times, the user inputs a value. This is done by prompting the user to enter data by displaying a text box or question on the screen. For example, the following code will store a user’s name:
name=input(“What is your name?”)

Variables Report Information

By using the variable name in a sentence you can report important information to the user. For instance, to display a player’s score the following code will join text with the variable value:
print(“The game is over. Your score is ” +str(score)).

Variables Personalize the User’s Experience

Variables can be used to communicate, making a device seem more human or less machine-like. Suppose that a player types in their name. Lines of code can have the computer give a personal greeting, such as Hello Sara. The sentence and variable are put together using this Python code: print(“Hello ” +str(player)).

Variables Can Trigger an Action

A variable’s value can change. If it is a number, it can get higher or lower. If it is a text, it could have another value assigned to it. Conditional logic can be used to trigger an action when a variable meets a specific condition. The value of the variable might need to be equal to, greater than, less than, or does not equal. When the variable value matches the condition, then an action will occur. The code might start like this if guess==”answer”:

Variables Calculate Amounts

Variables can be used in mathematical formulas. This has many practical applications. For example, a business owner can track employee earnings. The variables wage, hours_worked, and earnings can be placed into the formula earnings=wage*hours_worked.

Create Artwork and Build Games using Variables in Python to Teach Coding

Learning how to use variables in Python can be fun. In TechnoTurtle, the programming activities gradually introduce elementary and middle school students to variables. In this project they use variables to count loops and create spirographs that are random colors. As well, they store player answers to build a Mad Lib word game, a carnival game that awards a prize, and a guessing game. These programming tasks make the purpose of a variable easy to understand. Beginners experience first-hand how variables are used in a program to complete a task.

Learning about variables can be fun.