In your university, if you are getting zero scores in your programming assignments, even after developing a logically correct code, then it is high time to focus on the “Checklist for Autograder-Safe Coding”.
Autograder is a complicated machine where writing a logically correct code is not the whole thing. An Autograder judges your programs based on the format, input-output consistency, and some pre-defined rules.
In this article, we are going to first learn about the Autograders and why they reject a logically correct code. Later, we will develop an ultimate checklist that will help you write an Autograder-safe code. So, let us start.
TL;DR: Checklist For Autograder-Safe Coding
Aspect | Summary |
What Is An Autograder? | It is an automated system that evaluates programming assignments using predefined test cases and output formats without human involvement. |
Why Codes Get Rejected? | Mismatches like extra spaces, missing inputs, wrong data types, incorrect class names, or unhandled edge cases lead to rejections. |
Autograder-Safe Coding Checklist |
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Real Example | A real Python Problem Statement has been taken with the following:
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What Is An Autograder? Read Below
An Autograder is an automated system that evaluates your programming assignments without any human interaction. Any university, coding platform, or online learning tool uses Autograders for evaluation.
In an Autograder, some predefined test cases and output formats were already given. The Autograder checks your code on those test cases, and if your output matches the given output, then the code passes; otherwise, it fails.
Why Do Autograders Reject Logically Correct Codes?
In Autograder, the code logic is not everything. Your code might get rejected for the following reasons:
- The output is not matched with the given one. Some extra spaces, text, or anything has been added.
- The code is not taking input values from the user; rather, the values are provided in the code.
- Using a different class name or local name instead of the predefined name mentioned in the problem.
- Any kind of runtime error due to any edge cases or test cases present in Autograder.
Programming homework and assignments are based on logic-building and problem-solving cases, which might often be confusing for students, especially those who have just started with computer science. So, paying for programming homework help can be a smart option if you’re stuck on a bug or can’t solve a problem on your own.
The Ultimate Autograder-Safe Coding Checklist For Students:
We hope that the background of the Autograder and why even a logically correct code gets failed in Autograder has become clear to you. Now, it is time to understand how to write an Autograder-safe code.
For that purpose, you have to go through the following checklist points carefully. So, let us go through them.
1. Understand The Input Instructions:
The first and very important reason for which a program can be rejected by the Autograder is the mismatched input format. You have to understand what the program is asking from you as the input.
This thing can be written as a sample in your problem or might even be mentioned in a shown test case. From that, you have to point out the input instructions and develop the code by following them.
The following tips you can use to avoid any misunderstanding with the Autograder input instructions:
- While taking the input, don’t use any more prompt text like ‘Enter A Value’ or ‘First Number’.
- Use the input() or relevant functions only to take the input from the user.
- Collect the correct input format, like if the program needs FLOAT, then don’t take DOUBLE values.
2. Match The Provided Output Format:
Not only do you have to understand the input instructions, but you also have to understand the Output Format. The input and output are mainly responsible for a code being rejected by the Autograder. So, be careful with this.
Whatever the output format is mentioned in the problem statement, you have to follow it. You can’t even add a simple space or newline in the output, as the Autograder is very sensitive towards them.
You can use the following tips to match your output with the provided output format in the Autograder:
- Don’t write any prompt text, newline, space, or blank line after the Print statement.
- If the output is asking for the Value 3.00, then you have to provide the same, not the Value 3.
- For fixed decimal values, you have to do the String Formatting using Python F-strings.
3. Handle All The Edge Cases:
Autograder highly relies on the Test Cases. Among them, some are shown to you for your better understanding of the problem, and most are hidden, which creates the issues and determines the fate of the assignment.
In the hidden test cases, some extreme conditions can be present, like working with Zeros, Negative Values, or even large values. The purpose of this is to check the functionality of your code in such extreme conditions.
To handle all the edge cases in the Autograder gracefully, the following tips can certainly be followed.
- Read the question carefully, from where you can anticipate what kind of extreme test cases can be there.
- Develop the Conditional Statement, like If-Else, in your code to work on such edge cases.
- Try to check your code with all types of possible extreme edge cases by your own on the local machine.
4. Don’t Use Hardcoded Values:
Another big mistake that most students make in Autograder is by giving the Hardcoded Values in the code. You have to always remember that Autograders never accept hardcoded values.
In every test case, a set of input values is given. Those input values should be accepted by the code. Hence, you have to use the input() or equivalent functions to take user input, not the hardcoded values.
You can go through the following tips to more clearly understand these checklist points.
- Don’t assume the input values from the given question. Always take user input.
- Use the Input() for Python and Scanner() for Java without any prompt input text.
- Don’t develop the code using only the Sample Inputs. Keep in mind, there are more input values in hidden test cases.
5. Use The Correct Indentation And Syntax:
This point is very important for beginner-level programmers. The Indentation and Syntax matter more than any other points. If the indentation and syntax are not correct, the Autograder will reject it without even testing.
If you are developing code in Python, then you have to give great focus on the indentation, and for Java and C++, the code blocks should be written in the correct format. The code should be structured and readable.
The following tips can be used to develop the correct indentation and syntax in Autograder code.
- As a beginner, develop the code in an IDE first, where indentations are properly marked.
- In the IDE, if possible, run a Syntax Check in the terminal for better results.
- During indentation, use either the Space or Tab. Don’t mix both of them.
6. Write In The Given Function Or Class Name:
Sometimes, you have to develop the code in a given Function or Class Name. That Function or Class Name is the starting point for the Autograder from which it will check your code. So, that is very important.
But, if you do not mention that Function or Class Name in your code and use any local name, then the Autograder can’t even go through the code and reject it. So, use the given function or class name only in Autograder.
The following tips can help you more in this regard to use the give function or class name:
- Use the function or class name mentioned in the problem statement, like ‘def calculate()’.
- Use the given spelling and word case because the function name is case-sensitive in the Autograder.
- If the Main Class or Method is pre-written in the Autograder, then don’t rename it forcefully.
7. Submit In The Correct File Format:
The last but not least one is the submission of the correct file format. Some Autograders don’t give you the space to develop the code there, which means no code editor comes up with them. In such cases, you have to upload.
Even if you have developed a logically correct code and an Autograder-safe code, it can get rejected as the File Format is not correct. So, you have to be very careful if your university is asking you to upload the code file.
You can use the following tips to upload a correct code file in the Autograder, which will be accepted:
- Use the same file name in the same case mentioned in the question, like Main.java, solution.py, etc.
- You have to be careful with the File Extension and its case, like using .py instead of .PY.
- Upload only the code file. Don’t upload associated files like .exe, .class, etc.
Real Example: Developing An Autograder-Safe Code On A Problem
After such an extensive discussion, we hope you are now ready to develop some Autograder-safe code in the future. However, if you still have any doubts about the practical implementation, then this section is for you.
Here, we will take a real problem statement and develop an Autograder-safe code. So, let us go through it.
Problem Statement: Write a Python function called calculate_zap() that reads two integers and prints their sum.
Autograder Unsafe Code:
This is the wrong code developed by a student that will be rejected by the Autograder. Let us check it first.
def sumcalc(): # Wrong Class Name
print("Enter first number:") # Unnecessary Input Prompt
a = float(input()) # Indentation Is Not Matching And Wrong Data Type Has Been Used
print("Enter second number:") # Unnecessary Input Prompt
b = float(input()) # Indentation Is Not Matching, And The Wrong Data Type Has Been Used
print("Sum is:", a + b) # Unnecessary Output Prompt
This code was rejected by the Autograder for the following reasons. Let us understand the faults.
- The Class Name is used incorrectly here. The correct class name should be calculate_zap().
- Unnecessary input prompts and the Wrong data type have been used for both the integer values.
- To print the output, the unnecessary output prompt data is used.
Autograder Safe Code:
Now, we will recreate a different version of the above code. This code will now be accepted by the Autograder.
def calculate_zap(): # The Correct Function Name
try: # Try-Except Block For Edge Case Handling
# Taking Inputs Without Prompts And In Correct Format
a = int(input().strip())
b = int(input().strip())
print(a + b) # Printing Without Prompt
except:
print("Give Proper Input")
Let us check why this code will be accepted by the Autograder. The points are mentioned in the following.
- The given function name has been used, and a Try-Except Block has been used for edge case handling.
- No input prompts have been used, and data has been taken in Integer Format, not in Float Format.
- The Output is giving only the result, not any prompt text.
A Printable Mini Student Checklist For Autograder-Safe Coding:
In the end, we know, it is very tough to remember all of these checklist points during your programming work on any Autograder. But don’t get worried about this issue, as we have a fix for this problem as well.
In this section, we have brought a Printable Mini Checklist for Autograder-safe Coding. Download and print it. Then, you can pin it on your desk, which will help you to submit safe programs in the Autograder.
Key Takeaways:
- Autograder is an automated system used by universities to check programs without any human intervention.
- Writing logically correct code is not enough in an Autograder; you also have to pass predefined rules.
- Mismatched outputs, hardcoded inputs, wrong class, etc., are some reasons behind Autograder rejection.
- Matching input and output, correct indentation, class name, and handling edge cases are the fixes.
