Sample code for the article on for loops

python-for-loop/README.md

@@ -0,0 +1,3 @@
+# Python "for" Loops: The Pythonic Way
+
+This folder provides the code examples for the Real Python tutorial [Python "for" Loops: The Pythonic Way](https://realpython.com/python-for-loop-update/).

python-for-loop/async_range.py

@@ -0,0 +1,19 @@
+import asyncio
+
+
+class AsyncRange:
+    def __init__(self, start, end):
+        self.data = range(start, end)
+
+    async def __aiter__(self):
+        for index in self.data:
+            await asyncio.sleep(0.5)
+            yield index
+
+
+async def main():
+    async for index in AsyncRange(0, 5):
+        print(index)
+
+
+asyncio.run(main())

python-for-loop/break_continue.py

@@ -0,0 +1,14 @@
+numbers = [1, 3, 5, 7, 9]
+target = 5
+for number in numbers:
+    print(f"Processing {number}...")
+    if number == target:
+        print(f"Target found {target}!")
+        break
+
+numbers = [1, 2, 3, 4, 5, 6]
+for number in numbers:
+    print(f"{number = }")
+    if number % 2 != 0:
+        continue
+    print(f"{number} is even!")

python-for-loop/built_in_types.py

@@ -0,0 +1,14 @@
+numbers = [1, 2, 3, 4]
+for number in numbers:
+    print(number)
+
+person = ("Jane", 25, "Python Dev", "Canada")
+for field in person:
+    print(field)
+
+text = "abcde"
+for character in text:
+    print(character)
+
+for index in range(5):
+    print(index)

python-for-loop/colors.py

@@ -0,0 +1,4 @@
+colors = ["red", "green", "blue", "yellow"]
+
+for color in colors:
+    print(color)

python-for-loop/cubes.py

@@ -0,0 +1,7 @@
+cubes = []
+for number in range(10):
+    cubes.append(number**3)
+print(cubes)
+
+cubes = [number**3 for number in range(10)]
+print(cubes)

python-for-loop/dictionaries.py

@@ -0,0 +1,29 @@
+students = {
+    "Alice": 89.5,
+    "Bob": 76.0,
+    "Charlie": 92.3,
+    "Diana": 84.7,
+    "Ethan": 88.9,
+}
+for student in students:
+    print(student)
+
+for student in students:
+    print(student, "->", students[student])
+
+for student in students.keys():
+    print(student)
+
+teams = {
+    "Colorado": "Rockies",
+    "Chicago": "White Sox",
+    "Boston": "Red Sox",
+    "Minnesota": "Twins",
+    "Milwaukee": "Brewers",
+    "Seattle": "Mariners",
+}
+for team in teams.values():
+    print(team)
+
+for city, team in teams.items():
+    print(city, "->", team)

python-for-loop/else_clause.py

@@ -0,0 +1,10 @@
+numbers = [1, 3, 5, 7, 9]
+target = 42
+
+for number in numbers:
+    print(f"Processing {number}...")
+    if number == target:
+        print(f"Target found {target}!")
+        break
+else:
+    print(f"Target no found {target}")

python-for-loop/exceptions.py

@@ -0,0 +1,14 @@
+files = ["file1.txt", "file2.txt", "file3.txt"]
+
+for file in files:
+    with open(file, "r") as f:
+        print(f"Contents of {file}:")
+        print(f.read())
+
+for file in files:
+    try:
+        with open(file, "r") as f:
+            print(f"Contents of {file}:")
+            print(f.read())
+    except FileNotFoundError:
+        print(f"Error: {file} not found. Skipping.")

python-for-loop/indices.py

@@ -0,0 +1,8 @@
+fruits = ["orange", "apple", "mango", "lemon"]
+
+for index in range(len(fruits)):
+    fruit = fruits[index]
+    print(index, fruit)
+
+for index, fruit in enumerate(fruits):
+    print(index, fruit)

python-for-loop/matrix.py

@@ -0,0 +1,10 @@
+from itertools import chain
+
+matrix = [
+    [9, 3, 8],
+    [4, 5, 2],
+    [6, 4, 3],
+]
+
+for value in chain(*matrix):
+    print(value**2)

python-for-loop/menu.py

@@ -0,0 +1,7 @@
+def display_menu(options):
+    print("Main Menu:")
+    for pos, option in enumerate(options, start=1):
+        print(f"{pos}. {option}")
+
+
+display_menu(["Open", "Save", "Settings", "Quit"])

python-for-loop/nested.py

@@ -0,0 +1,4 @@
+for number in range(1, 11):
+    for product in range(number, number * 11, number):
+        print(f"{product:>4d}", end="")
+    print()

python-for-loop/parallel_iteration.py

@@ -0,0 +1,5 @@
+numbers = [1, 2, 3]
+letters = ["a", "b", "c"]
+
+for number, letter in zip(numbers, letters):
+    print(number, "->", letter)

python-for-loop/repeat.py

@@ -0,0 +1,3 @@
+for _ in range(3):
+    print("Knock, knock, knock")
+    print("Penny!")

python-for-loop/reversing.py

@@ -0,0 +1,4 @@
+actions = ["Type text", "Select text", "Cut text", "Paste text"]
+
+for action in reversed(actions):
+    print(f"Undo: {action}")

python-for-loop/sets.py

@@ -0,0 +1,4 @@
+tools = {"Django", "Flask", "pandas", "NumPy"}
+
+for tool in tools:
+    print(tool)

python-for-loop/sorting.py

@@ -0,0 +1,17 @@
+students = {
+    "Alice": 89.5,
+    "Bob": 76.0,
+    "Charlie": 92.3,
+    "Diana": 84.7,
+    "Ethan": 88.9,
+    "Fiona": 95.6,
+    "George": 73.4,
+    "Hannah": 81.2,
+}
+
+sorted_students = sorted(
+    students.items(), key=lambda item: item[1], reverse=True
+)
+
+for name, grade in sorted_students:
+    print(f"{name}'s average grade: {grade:->{20-len(name)}.1f}")

python-for-loop/unpacking.py

@@ -0,0 +1,4 @@
+points = [(1, 4), (3, 6), (7, 3)]
+
+for x, y in points:
+    print(f"{x = } and {y = }")