Input validation and sanitization in Agentic AI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the input is a non-empty string.

Agentic AI

def is_valid_input(user_input):
    return isinstance(user_input, [1]) and len(user_input) > 0

Drag options to blanks, or click blank then click option'

Astr

Bint

Clist

Ddict

Attempts:

3 left

💡 Hint

Common Mistakes

Using int or list instead of str

Not checking the length of the input

The function checks if the input is a string and not empty. Using str ensures the input is text.

2fill in blank

medium

Complete the code to remove leading and trailing spaces from the input string.

Agentic AI

def sanitize_input(user_input):
    return user_input.[1]()

Drag options to blanks, or click blank then click option'

Areplace

Bsplit

Cstrip

Dlower

Attempts:

3 left

💡 Hint

Common Mistakes

Using split() which splits the string

Using replace() without specifying what to replace

The strip() method removes spaces from the start and end of a string, cleaning the input.

3fill in blank

hard

Fix the error in the code to safely convert input to an integer.

Agentic AI

def convert_to_int(user_input):
    try:
        return [1](user_input)
    except ValueError:
        return None

Drag options to blanks, or click blank then click option'

Abool

Bint

Cfloat

Dstr

Attempts:

3 left

💡 Hint

Common Mistakes

Using str() which does not convert to int

Using float() which converts to decimal numbers

The int() function converts a string to an integer. The try-except block handles invalid inputs safely.

4fill in blank

hard

Fill both blanks to create a dictionary of word lengths for words longer than 3 characters.

Agentic AI

words = ['apple', 'cat', 'banana', 'dog']
lengths = {word: [1] for word in words if len(word) [2] 3}

Drag options to blanks, or click blank then click option'

Alen(word)

B>

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using word instead of len(word)

Using < instead of > in the condition

The dictionary comprehension maps each word to its length if the word length is greater than 3.

5fill in blank

hard

Fill all three blanks to filter and transform a dictionary with values greater than 0.

Agentic AI

data = {'a': 1, 'b': -2, 'c': 3}
result = {{ [1]: [2] for k, v in data.items() if v [3] 0 }}

Drag options to blanks, or click blank then click option'

Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using k instead of k.upper()

Using < instead of > in the condition

The comprehension creates a new dictionary with keys in uppercase and values unchanged, only for values greater than zero.

Practice

1. What is the main purpose of input validation in machine learning systems?

easy

A. To train the model with new data

B. To clean the data by removing unwanted characters

C. To check if the input data is the correct type and format

D. To store data securely in a database

Solution

1. Step 1: Understand input validation

   Input validation means checking if the data is the right type and format before using it.

2. Step 2: Differentiate from sanitization

   Input sanitization cleans data, but validation focuses on correctness and format.

3. Final Answer:

   To check if the input data is the correct type and format -> Option C

4. Quick Check:

   Input validation = Check data type and format [OK]

Hint: Validation means checking data type and format [OK]

Common Mistakes:

• Confusing validation with sanitization
• Thinking validation trains the model
• Assuming validation stores data

2. Which of the following is the correct way to validate that an input is a positive integer in Python?

easy

A. if isinstance(input_value, int) and input_value > 0:

B. if type(input_value) == 'int' and input_value > 0:

C. if input_value.isdigit() and input_value > 0:

D. if input_value > 0:

Solution

1. Step 1: Check type correctly

   Use isinstance(input_value, int) to check if input is an integer.

2. Step 2: Check positivity

   Ensure the integer is greater than zero with input_value > 0.

3. Final Answer:

   if isinstance(input_value, int) and input_value > 0: -> Option A

4. Quick Check:

   Use isinstance and > 0 for positive integer check [OK]

Hint: Use isinstance() to check type, then compare value [OK]

Common Mistakes:

• Using type() == 'int' (wrong syntax)
• Calling isdigit() on non-string input
• Skipping type check before comparison

3. Given the code below, what will be the output?

def sanitize_input(text):
    return text.strip().lower()

user_input = '  Hello World!  '
cleaned = sanitize_input(user_input)
print(cleaned)

medium

A. Hello World!

B. !dlroW olleH

C. HELLO WORLD!

D. hello world!

Solution

1. Step 1: Understand strip()

   The strip() method removes spaces from the start and end of the string.

2. Step 2: Understand lower()

   The lower() method converts all letters to lowercase.

3. Final Answer:

   hello world! -> Option D

4. Quick Check:

   strip + lower = 'hello world!' [OK]

Hint: strip removes spaces, lower makes all letters small [OK]

Common Mistakes:

• Ignoring strip() effect on spaces
• Confusing lower() with upper()
• Expecting original casing in output

4. Identify the error in this input validation code snippet:

def validate_age(age):
    if age.isdigit() and age > 0:
        return True
    else:
        return False

medium

A. Comparing string with integer using > operator

B. Using isdigit() on a non-string type

C. Missing return statement in else block

D. Function name is invalid

Solution

1. Step 1: Check isdigit() usage

   isdigit() works on strings, so age should be a string here.

2. Step 2: Identify type mismatch in comparison

   Comparing age > 0 compares string to int, which causes error.

3. Final Answer:

   Comparing string with integer using > operator -> Option A

4. Quick Check:

   String > int comparison causes error [OK]

Hint: Check types before comparing values [OK]

Common Mistakes:

• Assuming isdigit() converts type
• Ignoring type mismatch in comparisons
• Thinking function name affects validation

5. You receive user data as a list of strings representing ages: ['25', ' 30', 'twenty', '40', '']. Which code snippet correctly validates and sanitizes this data to keep only valid positive integers?

hard

A. valid_ages = [age for age in ages if age.isdigit() and age > 0]

B. valid_ages = [int(age.strip()) for age in ages if age.strip().isdigit() and int(age.strip()) > 0]

C. valid_ages = [int(age) for age in ages if age.isnumeric()]

D. valid_ages = [int(age) for age in ages if age.strip() != '']

Solution

1. Step 1: Sanitize input by stripping spaces

   Use age.strip() to remove spaces before validation.

2. Step 2: Validate with isdigit() and positive check

   Check if stripped string is digits only and convert to int to check > 0.

3. Step 3: Convert valid strings to integers

   Use int(age.strip()) to convert valid strings to integers.

4. Final Answer:

   valid_ages = [int(age.strip()) for age in ages if age.strip().isdigit() and int(age.strip()) > 0] -> Option B

5. Quick Check:

   Strip spaces, check digits, convert to int > 0 [OK]

Hint: Strip spaces before isdigit(), then convert and check > 0 [OK]

Common Mistakes:

• Not stripping spaces before validation
• Comparing strings directly to numbers
• Including empty or non-digit strings