Search parameter in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this REST API search parameter example?

Consider a REST API endpoint that supports a search parameter to filter users by age greater than 30.

Given the following request URL:

GET /users?age_gt=30

And the server code snippet that filters users:

users = [
  {"name": "Alice", "age": 25},
  {"name": "Bob", "age": 35},
  {"name": "Charlie", "age": 40}
]

filtered = [user for user in users if user["age"] > int(request.args.get("age_gt", 0))]
print(filtered)

What will be printed?

Rest API

users = [
  {"name": "Alice", "age": 25},
  {"name": "Bob", "age": 35},
  {"name": "Charlie", "age": 40}
]

class Request:
    def __init__(self):
        self.args = {"age_gt": "30"}

request = Request()

filtered = [user for user in users if user["age"] > int(request.args.get("age_gt", 0))]
print(filtered)

A [{'name': 'Bob', 'age': 35}, {'name': 'Charlie', 'age': 40}]

B [{'name': 'Alice', 'age': 25}]

C []

D [{'name': 'Alice', 'age': 25}, {'name': 'Bob', 'age': 35}, {'name': 'Charlie', 'age': 40}]

💡 Hint

Think about which users have age greater than 30.

The code filters users whose age is greater than 30. Alice is 25, so excluded. Bob and Charlie are 35 and 40, so included.

🧠 Conceptual

intermediate

Which HTTP method is typically used with search parameters in REST APIs?

When you want to retrieve data filtered by search parameters in a REST API, which HTTP method should you use?

A POST

B PUT

C GET

D DELETE

💡 Hint

Think about which method is used to get data without changing it.

GET is used to retrieve data and can include search parameters in the URL query string.

🔧 Debug

advanced

What error does this search parameter code raise?

Look at this code snippet that tries to filter products by a minimum price from a search parameter:

products = [
  {"name": "Pen", "price": 1.5},
  {"name": "Notebook", "price": 3.0}
]

min_price = request.args.get("min_price")
filtered = [p for p in products if p["price"] >= min_price]
print(filtered)

What error will this code raise when the request URL is /products?min_price=2?

Rest API

products = [
  {"name": "Pen", "price": 1.5},
  {"name": "Notebook", "price": 3.0}
]

class Request:
    def __init__(self):
        self.args = {"min_price": "2"}

request = Request()

min_price = request.args.get("min_price")
filtered = [p for p in products if p["price"] >= min_price]
print(filtered)

A No error, prints all products

B SyntaxError: invalid syntax

C KeyError: 'min_price'

D TypeError: '>=' not supported between instances of 'float' and 'str'

💡 Hint

Check the types of p["price"] and min_price.

The min_price is a string from the request arguments. Comparing float >= string causes a TypeError.

📝 Syntax

advanced

Which option correctly extracts a search parameter 'category' from a Flask request?

In a Flask app, you want to get the 'category' search parameter from the URL query string. Which code snippet is correct?

A category = request.args.get('category', default='all')

B category = request.get.args('category')

C category = request.args['category']()

D category = request.args.get['category']

💡 Hint

Remember the syntax for getting query parameters in Flask.

request.args.get('category', default='all') correctly gets the parameter with a default value.

🚀 Application

expert

How many items are returned by this complex search parameter filter?

Given this list of books and a search parameter 'year' filtering books published after that year:

books = [
  {"title": "Book A", "year": 1999},
  {"title": "Book B", "year": 2005},
  {"title": "Book C", "year": 2010},
  {"title": "Book D", "year": 2015}
]

search_year = int(request.args.get("year", "2000"))
filtered_books = [b for b in books if b["year"] > search_year]
print(len(filtered_books))

If the request URL is /books?year=2005, how many books will be printed?

Rest API

books = [
  {"title": "Book A", "year": 1999},
  {"title": "Book B", "year": 2005},
  {"title": "Book C", "year": 2010},
  {"title": "Book D", "year": 2015}
]

class Request:
    def __init__(self):
        self.args = {"year": "2005"}

request = Request()

search_year = int(request.args.get("year", "2000"))
filtered_books = [b for b in books if b["year"] > search_year]
print(len(filtered_books))

A 4

B 2

C 1

D 3

💡 Hint

Count books with year greater than 2005.

Books C (2010) and D (2015) have year > 2005, so 2 books.