python: various updates

exercises/python-in-practice/fastapi_contacts/data.json

@@ -0,0 +1,16 @@
+{
+  "contacts": [
+    {
+      "id": 1,
+      "first_name": "John",
+      "last_name": "Doe",
+      "phone_nr": "+123456789"
+    },
+    {
+      "id": 2,
+      "first_name": "Jane",
+      "last_name": "Doe",
+      "phone_nr": "+987654321"
+    }
+  ]
+}

exercises/python-in-practice/fastapi_contacts/main.py

@@ -0,0 +1,104 @@
+from typing import Optional
+from fastapi import FastAPI, HTTPException
+from pydantic import BaseModel
+import json
+
+
+class Contact(BaseModel):
+    id: int
+    first_name: str
+    last_name: str
+    phone_nr: str
+
+
+app = FastAPI()
+
+
+def load_contacts():
+    with open("./data.json", encoding="utf-8") as data_file:
+        contents = json.load(data_file)
+    contacts = contents["contacts"]
+    return contacts
+
+
+def save_contacts(contacts):
+    with open("./data.json", "w", encoding="utf-8") as data_file:
+        json.dump({"contacts": contacts}, data_file, indent=2)
+
+
+@app.get("/")
+def read_contacts(first_name: str = None):
+    result = []
+    contacts = load_contacts()
+    if first_name:
+        for contact in contacts:
+            if first_name.lower() in contact["first_name"].lower():
+                result.append(contact)
+        return result
+    else:
+        return contacts
+
+
+@app.get("/{contact_id}")
+def read_contact(contact_id: int):
+    contacts = load_contacts()
+    for contact in contacts:
+        if contact["id"] == contact_id:
+            return contact
+    raise HTTPException(status_code=404, detail="item not found")
+
+
+@app.post("/")
+def add_contact(first_name: str, last_name: str, phone_nr: str):
+    contacts = load_contacts()
+    max_id = 0
+    for c in contacts:
+        if c["id"] > max_id:
+            max_id = c["id"]
+    contact = {
+        "id": max_id + 1,
+        "first_name": first_name,
+        "last_name": last_name,
+        "phone_nr": phone_nr,
+    }
+    contacts.append(contact)
+    save_contacts(contacts)
+
+
+@app.put("/{contact_id}")
+def replace_contact(contact_id: int, first_name: str, last_name: str, phone_nr: str):
+    contacts = load_contacts()
+    for (i, contact) in enumerate(contacts):
+        if contact["id"] == contact_id:
+            contacts[i] = {
+                "id": contact_id,
+                "first_name": first_name,
+                "last_name": last_name,
+                "phone_nr": phone_nr,
+            }
+            break
+    save_contacts(contacts)
+
+
+@app.patch("/{todo_id}")
+def modify_contact(
+    contact_id: int, first_name: str = None, last_name: str = None, phone_nr: str = None
+):
+    contacts = load_contacts()
+    for contact in contacts:
+        if contact["id"] == contact_id:
+            if first_name:
+                contact["first_name"] = first_name
+            if last_name:
+                contact["last_name"] = last_name
+            if phone_nr:
+                contact["phone_nr"] = phone_nr
+            break
+    save_contacts(contacts)
+
+
+@app.delete("/{todo_id}")
+def delete_contact(contact_id: int):
+    contacts = load_contacts()
+    new_contacts = [c for c in contacts if c["id"] != contact_id]
+    save_contacts(new_contacts)

exercises/python-in-practice/web_api_fastapi/data.json → exercises/python-in-practice/fastapi_todos/data.json

@@ -1,14 +1,14 @@
-{
-  "todos": [
-    {
-      "id": 1,
-      "title": "abc",
-      "completed": false
-    },
-    {
-      "id": 3,
-      "title": "xyz",
-      "completed": false
-    }
-  ]
-}
+{
+  "todos": [
+    {
+      "id": 1,
+      "title": "abc",
+      "completed": false
+    },
+    {
+      "id": 3,
+      "title": "xyz",
+      "completed": false
+    }
+  ]
+}

exercises/python-in-practice/web_api_fastapi/main.py → exercises/python-in-practice/fastapi_todos/main.py

@@ -1,3 +1,6 @@
+# start with:
+# uvicorn main:app --reload
+
 from fastapi import FastAPI, HTTPException
 from pydantic import BaseModel
 import json
@@ -22,20 +25,10 @@ def load_todos():
 
 def save_todos(todos):
     data_file = open("./data.json", "w", encoding="utf-8")
-    content = json.dump({"todos": todos}, data_file, indent=2)
+    json.dump({"todos": todos}, data_file, indent=2)
     data_file.close()
 
 
-@app.get("/")
-def read_root():
-    return {"Hello": "World"}
-
-
-@app.get("/items/{item_id}")
-def read_item(item_id: int, q: str = None):
-    return {"item_id": item_id, "q": q}
-
-
 @app.get("/todos/")
 def read_todos():
     todos = load_todos()
@@ -45,10 +38,10 @@ def read_todos():
 @app.get("/todos/{todo_id}")
 def read_todo(todo_id: int):
     todos = load_todos()
-    filtered_todos = [todo for todo in todos if todo["id"] == todo_id]
-    if len(filtered_todos) == 0:
-        raise HTTPException(status_code=404, detail="Item not found")
-    return filtered_todos[0]
+    for todo in todos:
+        if todo["id"] == todo_id:
+            return todo
+    raise HTTPException(status_code=404, detail="Item not found")
 
 
 @app.post("/todos")
@@ -63,16 +56,16 @@ def add_todo(title: str):
     save_todos(todos)
 
 
-@app.put("/todos/{todo_id}")
-def modify_todo(todo_id: int, todo: Todo):
+@app.delete("/todos/{todo_id}")
+def delete_todo(todo_id: int):
     todos = load_todos()
-    filtered_todos = [todo for todo in todos if todo["id"] == todo_id]
-    if len(filtered_todos) == 0:
+    found_index = None
+    for index, todo in enumerate(todos):
+        if todo_id == todo["id"]:
+            found_index = index
+    if found_index is None:
         raise HTTPException(status_code=404, detail="todo not found")
-    t = filtered_todos[0]
-    t["id"] = todo.id
-    t["title"] = todo.title
-    t["completed"] = todo.completed
+    todos.pop(found_index)
     save_todos(todos)
 
 
@@ -90,14 +83,21 @@ def modify_todo(todo_id: int, title: str = None, completed: bool = None):
     save_todos(todos)
 
 
-@app.delete("/todos/{todo_id}")
-def delete_todo(todo_id: int):
+@app.put("/todos/{todo_id}")
+def modify_todo(todo_id: int, todo: Todo):
     todos = load_todos()
-    found_index = None
-    for index, todo in enumerate(todos):
-        if todo_id == todo["id"]:
-            found_index = index
-    if found_index is None:
+    filtered_todos = [todo for todo in todos if todo["id"] == todo_id]
+    if len(filtered_todos) == 0:
         raise HTTPException(status_code=404, detail="todo not found")
-    todos.pop(found_index)
+    t = filtered_todos[0]
+    t["id"] = todo.id
+    t["title"] = todo.title
+    t["completed"] = todo.completed
     save_todos(todos)
+
+
+@app.post("delete_completed_todos")
+def delete_completed_todos():
+    todos = load_todos()
+    filtered_todos = [t for t in todos if not t["completed"]]
+    save_todos(filtered_todos)

sections/python-advanced/50-iterators-de.md → sections/python-advanced/50-iterables-and-iterators-de.md

@@ -1,30 +1,61 @@
-# Iterators
+# Iterables und Iterators
 
 ## Iterables und Iterators
 
 _Iterable_: ein Objekt, über das mittels `for element in my_iterable` iteriert werden kann
 
-_Iterator_: ein leichtgewichtiges Iterable
+- "statisches _Iterable_": Elementenabfolge ist vordefiniert (z.B. _list_)
+- "dynamisches _Iterable_": Elemente werden während des Durchlaufs erzeugt (z.B. _range_)
 
 ## Iterables und Iterators
 
-Beispiele für Iterables:
+Hierarchie von Iterables:
 
-- lists
-- dicts
-- range-Objekte
-- iterators
-
-## Iterators
+- "statische Iterables" (z.B. _list_, _dict_)
+- "dynamische Iterables" (z.B. _range_)
+  - Iterators (z.B. _enumerate_, _os.scandir_)
+    - Generators (selbst-definiert)
 
-Ein _Iterator_ ist ein ressourcensparendes Iterable
+## Iterables und Iterators
 
-Mögliche Vorteile eines Iterators gegenüber Listen:
+Vorteile von "dynamischen Iterables" / Iterators:
 
 - Ressourcen werden nur bei Bedarf erstellt / abgefragt
 - Speicherverbrauch bleibt niedrig (nur je ein Element ist jeweils im Speicher)
 
-## Iterators
+## Iterables und Iterators
+
+Beispiele für "statische Iterables":
+
+- list
+- tuple
+- dict
+- string
+
+## Iterables und Iterators
+
+Beispiele für "dynamische Iterables":
+
+- range-Objekte
+- iterators
+
+## Iterables und Iterators
+
+Aufrufe, die Iterators zurückgeben:
+
+- `enumerate()`
+- `reversed()`
+- `open()`
+- `os.walk()`
+- `os.scandir()`
+- `map()`
+- `filter()`
+- Funktionen in _itertools_
+- üblicherweise Datenbankcursor (PEP 249)
+- Generators
+- ...
+
+## Iterables und Iterators
 
 Beispiel: `open()` gibt einen Iterator von Zeilen einer Datei zurück
 
@@ -34,9 +65,9 @@ with open("./foo.txt", encoding="utf-8") as f:
         print line
 ```
 
-Die Datei könnte mehrere GB oder größer sein und dieser Code würde problemlos laufen
+Die Datei könnte mehrere GB groß sein und dieser Code würde problemlos laufen
 
-## Iterators
+## Iterators und Iterators
 
 Beispielfunktionen:
 
@@ -54,23 +85,6 @@ for text in read_textfiles_as_iterator("./foo/"):
     print(text[:5])
 ```
 
-## Iterators
-
-Aufrufe, die Iterators zurückgeben:
-
-- `enumerate()`
-- `reversed()`
-- `open()`
-- `os.walk()`
-- `os.scandir()`
-- `map()`
-- `filter()`
-- Funktionen in _itertools_
-- üblicherweise Datenbankcursor (PEP 249)
-- ...
-
-Bemerkung: `range` gibt keinen Iterator zurück (aber ein ähnliches Objekt)
-
 ## Itertools
 
 [itertools](https://docs.python.org/3/library/itertools.html): Modul zum erstellen von Iterators