{ "cells": [ { "cell_type": "markdown", "id": "5c291475-8c7c-461c-9b12-545a887b2432", "metadata": {}, "source": [ "# Intermediate Level Python\n", "\n", "## A briefing on more advanced features of Python\n", "\n", "This section assumes you're up to speed on the foundations - and now we cover some important features of python that we use on the course.\n", "\n", "1. Comprehensions \n", "2. Generators \n", "3. Sub-classes, Type Hints, Pydantic \n", "4. Decorators\n", "5. Docker (not really python, but we use it to run python code!)\n" ] }, { "cell_type": "code", "execution_count": null, "id": "5802e2f0-0ea0-4237-bbb7-f375a34260f0", "metadata": {}, "outputs": [], "source": [ "# First let's create some things:\n", "\n", "fruits = [\"Apples\", \"Bananas\", \"Pears\"]\n", "\n", "book1 = {\"title\": \"Great Expectations\", \"author\": \"Charles Dickens\"}\n", "book2 = {\"title\": \"Bleak House\", \"author\": \"Charles Dickens\"}\n", "book3 = {\"title\": \"An Book By No Author\"}\n", "book4 = {\"title\": \"Moby Dick\", \"author\": \"Herman Melville\"}\n", "\n", "books = [book1, book2, book3, book4]" ] }, { "cell_type": "markdown", "id": "9b941e6a-3658-4144-a8d4-72f5e72f3707", "metadata": {}, "source": [ "# Part 1: List and dict comprehensions" ] }, { "cell_type": "code", "execution_count": null, "id": "61992bb8-735d-4dad-8747-8c10b63aec82", "metadata": {}, "outputs": [], "source": [ "# Simple enough to start\n", "\n", "for fruit in fruits:\n", " print(fruit)" ] }, { "cell_type": "code", "execution_count": null, "id": "c89c3842-9b74-47fa-8424-0fcb08e4177c", "metadata": {}, "outputs": [], "source": [ "# Let's make a new version of fruits\n", "\n", "fruits_shouted = []\n", "for fruit in fruits:\n", " fruits_shouted.append(fruit.upper())\n", "\n", "fruits_shouted" ] }, { "cell_type": "code", "execution_count": null, "id": "4ec13b3a-9545-44f1-874a-2910a0663560", "metadata": {}, "outputs": [], "source": [ "# You probably already know this\n", "# There's a nice Python construct called \"list comprehension\" that does this:\n", "\n", "fruits_shouted2 = [fruit.upper() for fruit in fruits]\n", "fruits_shouted2" ] }, { "cell_type": "code", "execution_count": null, "id": "ecc08c3c-181d-4b64-a3e1-b0ccffc6c0cd", "metadata": {}, "outputs": [], "source": [ "# But you may not know that you can do this to create dictionaries, too:\n", "\n", "fruit_mapping = {fruit: fruit.upper() for fruit in fruits}\n", "fruit_mapping" ] }, { "cell_type": "code", "execution_count": null, "id": "500c2406-00d2-4793-b57b-f49b612760c8", "metadata": {}, "outputs": [], "source": [ "# you can also use the if statement to filter the results\n", "\n", "fruits_with_longer_names_shouted = [fruit.upper() for fruit in fruits if len(fruit)>5]\n", "fruits_with_longer_names_shouted" ] }, { "cell_type": "code", "execution_count": null, "id": "38c11c34-d71e-45ba-945b-a3d37dc29793", "metadata": {}, "outputs": [], "source": [ "fruit_mapping_unless_starts_with_a = {fruit: fruit.upper() for fruit in fruits if not fruit.startswith('A')}\n", "fruit_mapping_unless_starts_with_a" ] }, { "cell_type": "code", "execution_count": null, "id": "5c97d8e8-31de-4afa-973e-28d8e5cab749", "metadata": {}, "outputs": [], "source": [ "# Another comprehension\n", "\n", "[book['title'] for book in books]" ] }, { "cell_type": "code", "execution_count": null, "id": "50be0edc-a4cd-493f-a680-06080bb497b4", "metadata": {}, "outputs": [], "source": [ "# This code will fail with an error because one of our books doesn't have an author\n", "\n", "[book['author'] for book in books]" ] }, { "cell_type": "code", "execution_count": null, "id": "53794083-cc09-4edb-b448-2ffb7e8495c2", "metadata": {}, "outputs": [], "source": [ "# But this will work, because get() returns None\n", "\n", "[book.get('author') for book in books]" ] }, { "cell_type": "code", "execution_count": null, "id": "b8e4b859-24f8-4016-8d74-c2cef226d049", "metadata": {}, "outputs": [], "source": [ "# And this variation will filter out the None\n", "\n", "[book.get('author') for book in books if book.get('author')]" ] }, { "cell_type": "code", "execution_count": null, "id": "c44bb999-52b4-4dee-810b-8a400db8f25f", "metadata": {}, "outputs": [], "source": [ "# And this version will convert it into a set, removing duplicates\n", "\n", "set([book.get('author') for book in books if book.get('author')])" ] }, { "cell_type": "code", "execution_count": null, "id": "80a65156-6192-4bb4-b4e6-df3fdc933891", "metadata": {}, "outputs": [], "source": [ "# And finally, this version is even nicer\n", "# curly braces creates a set, so this is a set comprehension\n", "\n", "{book.get('author') for book in books if book.get('author')}" ] }, { "cell_type": "markdown", "id": "c100e5db-5438-4715-921c-3f7152f83f4a", "metadata": {}, "source": [ "# Part 2: Generators\n", "\n", "We use Generators in the course because AI models can stream back results.\n", "\n", "If you've not used Generators before, please start with this excellent intro from ChatGPT:\n", "\n", "https://chatgpt.com/share/672faa6e-7dd0-8012-aae5-44fc0d0ec218\n", "\n", "Try pasting some of its examples into a cell." ] }, { "cell_type": "code", "execution_count": null, "id": "1efc26fa-9144-4352-9a17-dfec1d246aad", "metadata": {}, "outputs": [], "source": [ "# First define a generator; it looks like a function, but it has yield instead of return\n", "\n", "import time\n", "\n", "def come_up_with_fruit_names():\n", " for fruit in fruits:\n", " time.sleep(1) # thinking of a fruit\n", " yield fruit" ] }, { "cell_type": "code", "execution_count": null, "id": "eac338bb-285c-45c8-8a3e-dbfc41409ca3", "metadata": {}, "outputs": [], "source": [ "# Then use it\n", "\n", "for fruit in come_up_with_fruit_names():\n", " print(fruit)" ] }, { "cell_type": "code", "execution_count": null, "id": "f6880578-a3de-4502-952a-4572b95eb9ff", "metadata": {}, "outputs": [], "source": [ "# Here's another one\n", "\n", "def authors_generator():\n", " for book in books:\n", " if book.get(\"author\"):\n", " yield book.get(\"author\")" ] }, { "cell_type": "code", "execution_count": null, "id": "9e316f02-f87f-441d-a01f-024ade949607", "metadata": {}, "outputs": [], "source": [ "# Use it\n", "\n", "for author in authors_generator():\n", " print(author)" ] }, { "cell_type": "code", "execution_count": null, "id": "7535c9d0-410e-4e56-a86c-ae6c0e16053f", "metadata": {}, "outputs": [], "source": [ "# Here's the same thing written with list comprehension\n", "\n", "def authors_generator():\n", " for author in [book.get(\"author\") for book in books if book.get(\"author\")]:\n", " yield author" ] }, { "cell_type": "code", "execution_count": null, "id": "dad34494-0f6c-4edb-b03f-b8d49ee186f2", "metadata": {}, "outputs": [], "source": [ "# Use it\n", "\n", "for author in authors_generator():\n", " print(author)" ] }, { "cell_type": "code", "execution_count": null, "id": "abeb7e61-d8aa-4af0-b05a-ae17323e678c", "metadata": {}, "outputs": [], "source": [ "# Here's a nice shortcut\n", "# You can use \"yield from\" to yield each item of an iterable\n", "\n", "def authors_generator():\n", " yield from [book.get(\"author\") for book in books if book.get(\"author\")]" ] }, { "cell_type": "code", "execution_count": null, "id": "05b0cb43-aa83-4762-a797-d3beb0f22c44", "metadata": {}, "outputs": [], "source": [ "# Use it\n", "\n", "for author in authors_generator():\n", " print(author)" ] }, { "cell_type": "code", "execution_count": null, "id": "fdfea58e-d809-4dd4-b7b0-c26427f8be55", "metadata": {}, "outputs": [], "source": [ "# And finally - we can replace the list comprehension with a set comprehension\n", "\n", "def unique_authors_generator():\n", " yield from {book.get(\"author\") for book in books if book.get(\"author\")}" ] }, { "cell_type": "code", "execution_count": null, "id": "3e821d08-97be-4db9-9a5b-ce5dced3eff8", "metadata": {}, "outputs": [], "source": [ "# Use it\n", "\n", "for author in unique_authors_generator():\n", " print(author)" ] }, { "cell_type": "code", "execution_count": null, "id": "905ba603-15d8-4d01-9a79-60ec293d7ca1", "metadata": {}, "outputs": [], "source": [ "# And for some fun - press the stop button in the toolbar when bored!\n", "# It's like we've made our own Large Language Model... although not particularly large..\n", "# See if you understand why it prints a letter at a time, instead of a word at a time. If you're unsure, try removing the keyword \"from\" everywhere in the code.\n", "\n", "import random\n", "import time\n", "\n", "pronouns = [\"I\", \"You\", \"We\", \"They\"]\n", "verbs = [\"eat\", \"detest\", \"bathe in\", \"deny the existence of\", \"resent\", \"pontificate about\", \"juggle\", \"impersonate\", \"worship\", \"misplace\", \"conspire with\", \"philosophize about\", \"tap dance on\", \"dramatically renounce\", \"secretly collect\"]\n", "adjectives = [\"turqoise\", \"smelly\", \"arrogant\", \"festering\", \"pleasing\", \"whimsical\", \"disheveled\", \"pretentious\", \"wobbly\", \"melodramatic\", \"pompous\", \"fluorescent\", \"bewildered\", \"suspicious\", \"overripe\"]\n", "nouns = [\"turnips\", \"rodents\", \"eels\", \"walruses\", \"kumquats\", \"monocles\", \"spreadsheets\", \"bagpipes\", \"wombats\", \"accordions\", \"mustaches\", \"calculators\", \"jellyfish\", \"thermostats\"]\n", "\n", "def infinite_random_sentences():\n", " while True:\n", " yield from random.choice(pronouns)\n", " yield \" \"\n", " yield from random.choice(verbs)\n", " yield \" \"\n", " yield from random.choice(adjectives)\n", " yield \" \"\n", " yield from random.choice(nouns)\n", " yield \". \"\n", "\n", "for letter in infinite_random_sentences():\n", " print(letter, end=\"\", flush=True)\n", " time.sleep(0.02)" ] }, { "cell_type": "markdown", "id": "04832ea2-2447-4473-a449-104f80e24d85", "metadata": {}, "source": [ "# Exercise\n", "\n", "Write some python classes for the books example.\n", "\n", "Write a Book class with a title and author. Include a method has_author()\n", "\n", "Write a BookShelf class with a list of books. Include a generator method unique_authors()" ] }, { "cell_type": "markdown", "id": "35760406-fe6c-41f9-b0c0-3e8cf73aafd0", "metadata": {}, "source": [ "# Part 3: Sub-classes, Type Hints, Pydantic\n", "\n", "Here are some intermediate level details of Classes from our AI friend, including use of type hints, inheritance and class methods. This includes a Book example.\n", "\n", "https://chatgpt.com/share/67348aca-65fc-8012-a4a9-fd1b8f04ba59\n", "\n", "And here is a comprehensive tutorial on Pydantic classes covering everything you need to know about Pydantic.\n", "\n", "https://chatgpt.com/share/68064537-6cfc-8012-93e1-f7dd0932f321" ] }, { "cell_type": "markdown", "id": "6bbc9c63", "metadata": {}, "source": [ "## Part 4: Decorators\n", "\n", "Here is a briefing, with an example from OpenAI Agents SDK:\n", "\n", "https://chatgpt.com/share/6806474d-3880-8012-b2a2-87b3ee4489da" ] }, { "cell_type": "markdown", "id": "0beef7e9", "metadata": {}, "source": [ "## Part 5: Docker\n", "\n", "Here is a convenient tutorial to introduce Docker.\n", "\n", "In the last section, this also covers an answer to a question in Week 6 - what does it mean to run an MCP server in Docker? But you can ignore this question if you're not on week 6 yet.\n", "\n", "https://chatgpt.com/share/6814bc1d-2f3c-8012-9b18-dddc82ea421b" ] }, { "cell_type": "code", "execution_count": null, "id": "73e215b2", "metadata": {}, "outputs": [], "source": [ "# You need to install docker to run this example\n", "# This will download the Docker image for python 3.12, create a container,\n", "# Run some python code and print the result\n", "\n", "!docker run --rm python:3.12 python -c \"print(2 + 2)\"" ] } ], "metadata": { "kernelspec": { "display_name": ".venv", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.12.9" } }, "nbformat": 4, "nbformat_minor": 5 }