Exam Study Guide

The exam will cover Units 1 through 6 and homeworks 1 through 5.

Python: programming and best practices
- Writing code with: functions, loops, if-then, data structures, types
- Code organization: functions, classes, modules, libraries (packages), imports
- Maintaining package dependencies with uv
- Logging
- Programmatic testing
Data formats, primarily JSON
- What are the functions to read JSON from strings and from files?
- What kinds of data types can be serialized into JSON? What is an example of a data type that cannot be
serialized into JSON? * What are the functions for writing Python objects to JSON?
Pydantic data models
- Building classes from BaseModel, specifying types of fields.
- Building classes from other classes
Containers, specifically Docker
- Describe the concepts of Docker container, image, volume and network.
- What a Dockerfile is used for and some basic instructions including FROM, RUN, COPY, ENV
APIs and FastAPI
- The basic HTTP methods GET, POST, PUT, DELETE
- HTTP headers and the meaning of Content-type and Content-length
- HTTP response codes and the meaning of a 200 level, 400 level and 500 level response
- Basics of using curl and requests to make HTTP requests to a server.
- RESTful HTTP API architecture, including URL paths as collections, single items, and subcollections, and HTTP verbs for actions.
- Building HTTP APIs with FastAPI, including:
  - The app object and the @app decorators
  - Specifying request and response types
  - Specifying and working with URL path parameters
  - Specifying and working with URL query parameters

Example Exam Questions

Warning

This set of example questions is not intended to be a comprehensive study guide. Rather, it is only intended to give you a sense of the format of questions you will be asked. Be sure to review all of the topics in the previous section.

Short Answer

(True/False) A docker container is built from a Docker volume?
(True/False) An HTTP header is formatted as a name-value pair.
(True/False) If an API server is overloaded with too many requests from clients, it should return a 400-level error response.
(True/False) A Python library available in the standard library, such as the json library, must be installed using a tool like uv from PyPI, the Python Package Index.
(True/False) In Python, logs can be set at different levels to distinguish the severity or importance of the message being logged.
(True/False) In Python, a decorator returns a function.
(True/False) The HTTP method for creating a resource is PUT.
(True/False) Containers deployed to some server do NOT share an operating system.
(True/False) In order to define a new pydantic model, you must create a class that extends pydantic’s BaseModel
(True/False) In python json.loads converts a JSON-serialized string into a dictionary.
(True/False) You can defined nested paydantic models. i.e., a ShoppingCart model have an attribute items which is a list of ShoppingCartItem models.
(True/False) FastAPI ignore type hints in routes
(True/False) Pydantic models can NOT extend of pydantic models. Ex. Given model Animal(BaseModel), you can define a model like Dog(Animal).
(True/False) A standard endpoint for an HTTP server will have both a route (“/products”) and an HTTP verb
(True/False) In Python, you can use the type function to inspect the type of any object
(True/False) If you some code within an if statement like if __name__ == "__main__":, when the module that contains this code is imported, the code within that if statement will run.
(True/False) When testing your code using pytest, you should prefix your test function names with test_

Multiple choice

When working with a Dockerfile (select all that apply):

Use the COPY instruction to make a copy of a container.
The FROM instruction is used to define a pre-existing image as the starting point or base for the new image.
Use the docker build command to build the image defined by the Dockerfile.
Use the RUN instruction to run containers from the built image.

Which of thehe following Python objects are JSON-serializable (select all that apply):

A single string, such as "abc"
Boolean values, including True and False
The contents of an image file, such as a jpg file, read from disk using file.open().
The following list: [ {"a": 1, "key": True}, 7, "Another string", {"key": "value"}]

Which of the following HTTP methods should be used when creating a new resource:

GET
PUT
PATCH
DELETE
POST

Which of the following status codes should be returned when a user makes a mistake.

100
200
300
400
500

Complete the following decorator for a route that should return a list of courses: @app.______(“/courses”)

get
GET
post
POST
list
LIST

In your FastAPI application, a user requests a resource that does not exist so you raise the following Exception. raise HTTPException(status_code=_________). Complete the exception:

500
200
400
404
201

To see the headers when making a request using the command line utility curl , you must use which of the following flags:

-X
-d
-v
--help
--show-headers

Code Analysis

What will be the output of the following code?

data = [{"a": 1, "b": 2}, {"a": 3, "b": -1}, {"a": 4, "b": 1}]
def f(key):
    tot = 0
    for item in data:
        val = item[key]
        tot += val
    return tot

print(f("b"))

Writing Code: Part 1

Given the following code:

def get_data():
  return {
    "products": [
      {"id": 1, "name": "Apple", "price": .50},
      {"id": 2, "name": "Banana", "price": 10.00},
      {"id": 3, "name": "Coconut", "price": 4.50},
      {"id": 4, "name": "Pear", "price": 2.50},
      {"id": 5, "name": "Lettuce", "price": 1.50},
    ]
  }

Write a function that:

Takes a single argument that is a list of product dictionaries
Sums the value of all products
and returns that sum as a float
contains type hints for the argument and the return type

Call that function with the data returned from get_data and prints the result to stdout

Writing Code: Part 2

Given the following code:

from pydantic import BaseModel
from fastapi import FastAPI, HTTPException


app = FastAPI()

class Product(BaseModel):
  id: int
  name: str
  price: float

def get_data():
  return {
    "products": [
      {"id": 1, "name": "Apple", "price": .50},
      {"id": 2, "name": "Banana", "price": 10.00},
      {"id": 3, "name": "Coconut", "price": 4.50},
      {"id": 4, "name": "Pear", "price": 2.50},
      {"id": 5, "name": "Lettuce", "price": 1.50},
    ]
  }

Write 2 FastAPI routes.

Route 1

Converts the data returned by get_data into a list of pydantic models
Returns a list of products

@app.____("/_______________")
def list_products():
  # Fill in the code below

Route 2

Converts the data returned by get_data into a list of pydantic models
Returns a single product by the specified id
Raises an HTTPException with the correct status code if no product is found with the provided id.

@app.____("/_______________/{___}")
def get_product_by_id(___: ___):
  # Fill in the code below

Note

FastAPI allows you to return the pydantic models directly. The framework will serialize it for you