Add Python 3.11 examples from the final tutorial (#319)

* Add Python 3.11 examples from the final tutorial

* Linter

* Fix typo

* Final QA updates

Author: gahjelle

python-311/README.md

@@ -1,12 +1,12 @@
 import sys
 
 try:
-    raise ValueError("bpo-46328")
+    raise ValueError("gh-90486")
 except ValueError:
     print(f"Handling {sys.exception()}")
 
 # Typically you should prefer except ValueError as err:
 try:
-    raise ValueError("bpo-46328")
+    raise ValueError("gh-90486")
 except ValueError as err:
     print(f"Handling {err}")

python-311/active_exception.py

@@ -0,0 +1,7 @@
+import imghdr
+
+import magic
+
+print(imghdr.what("python-311.jpg"))
+
+print(magic.from_file("python-311.jpg"))

python-311/dead_imghdr.py

@@ -0,0 +1,30 @@
+import asyncio
+
+import aiohttp
+
+PEP_URL = (
+    "https://raw.githubusercontent.com/python/peps/master/pep-{pep:04d}.txt"
+)
+
+
+async def main(peps):
+    async with aiohttp.ClientSession() as session:
+        await download_peps(session, peps)
+
+
+async def download_peps(session, peps):
+    tasks = [asyncio.create_task(download_pep(session, pep)) for pep in peps]
+    await asyncio.gather(*tasks)
+
+
+async def download_pep(session, pep):
+    print(f"Downloading PEP {pep}")
+    url = PEP_URL.format(pep=pep)
+    async with session.get(url, params={}) as response:
+        pep_text = await response.text()
+
+    title = pep_text.split("\n")[1].removeprefix("Title:").strip()
+    print(f"Downloaded PEP {pep}: {title}")
+
+
+asyncio.run(main([492, 525, 530, 3148, 3156]))

python-311/download_peps_gather.py

@@ -0,0 +1,31 @@
+import asyncio
+
+import aiohttp
+
+PEP_URL = (
+    "https://raw.githubusercontent.com/python/peps/master/pep-{pep:04d}.txt"
+)
+
+
+async def main(peps):
+    async with aiohttp.ClientSession() as session:
+        await download_peps(session, peps)
+
+
+async def download_peps(session, peps):
+    async with asyncio.TaskGroup() as tg:
+        for pep in peps:
+            tg.create_task(download_pep(session, pep))
+
+
+async def download_pep(session, pep):
+    print(f"Downloading PEP {pep}")
+    url = PEP_URL.format(pep=pep)
+    async with session.get(url, params={}) as response:
+        pep_text = await response.text()
+
+    title = pep_text.split("\n")[1].removeprefix("Title:").strip()
+    print(f"Downloaded PEP {pep}: {title}")
+
+
+asyncio.run(main([492, 525, 530, 3148, 3156]))

python-311/download_peps_taskgroup.py

@@ -0,0 +1,5 @@
+def inverse(number):
+    return 1 / number
+
+
+print(inverse(0))

python-311/inverse.py

@@ -0,0 +1,13 @@
+from typing import TypeVar
+
+T0 = TypeVar("T0")
+T1 = TypeVar("T1")
+
+
+def flip(pair: tuple[T0, T1]) -> tuple[T1, T0]:
+    first, second = pair
+    return (second, first)
+
+
+pair = ("one", "two")
+print(f"{pair} -> {flip(pair)}")

python-311/pair_order.py

@@ -0,0 +1,23 @@
+[
+    {"name": {"first": "Uncle Barry"}},
+    {
+        "name": {"first": "Ada", "last": "Lovelace"},
+        "birth": {"year": 1815},
+        "death": {"month": 11, "day": 27}
+    },
+    {
+        "name": {"first": "Grace", "last": "Hopper"},
+        "birth": {"year": 1906, "month": 12, "day": 9},
+        "death": {"year": 1992, "month": 1, "day": 1}
+    },
+    {
+        "name": {"first": "Ole-Johan", "last": "Dahl"},
+        "birth": {"year": 1931, "month": 10, "day": 12},
+        "death": {"year": 2002, "month": 6, "day": 29}
+    },
+    {
+        "name": {"first": "Guido", "last": "Van Rossum"},
+        "birth": {"year": 1956, "month": 1, "day": 31},
+        "death": null
+    }
+]

python-311/programmers.json

@@ -0,0 +1,27 @@
+import json
+import pathlib
+from dataclasses import dataclass
+from typing import Any, Self, TypeAlias
+
+Info: TypeAlias = dict[str, Any]
+
+programmers = json.loads(
+    pathlib.Path("programmers.json").read_text(encoding="utf-8")
+)
+
+
+@dataclass
+class Person:
+    name: str
+    life_span: tuple[int, int]
+
+    @classmethod
+    def from_dict(cls, info: Info) -> Self:
+        return cls(
+            name=f"{info['name']['first']} {info['name']['last']}",
+            life_span=(info["birth"]["year"], info["death"]["year"]),
+        )
+
+
+def convert_pair(first: Info, second: Info) -> tuple[Person, Person]:
+    return Person.from_dict(first), Person.from_dict(second)