Merge pull request #579 from realpython/syntactic-sugar-python

Sample code for the article on syntactic sugar

Author: brendaweles

syntactic-sugar-python/README.md

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+# Syntactic Sugar: Why Python is Sweet and Pythonic
+
+This folder provides the code examples for the Real Python tutorial [Syntactic Sugar: Why Python is Sweet and Pythonic](https://realpython.com/python-syntactic-sugar/).

syntactic-sugar-python/assertions.py

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+number = 42
+if __debug__:
+    if not number > 0:
+        raise AssertionError("number must be positive")
+
+number = -42
+if __debug__:
+    if not number > 0:
+        raise AssertionError("number must be positive")

syntactic-sugar-python/balance.py

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+debit = 300
+credit = 450
+
+print(
+    f"Debit: ${debit:.2f}, Credit: ${credit:.2f}, Balance: ${credit - debit:.2f}"
+)
+
+print(
+    "Debit: ${:.2f}, Credit: ${:.2f}, Balance: ${:.2f}".format(
+        debit, credit, credit - debit
+    )
+)
+
+print(
+    "Debit: $"
+    + format(debit, ".2f")
+    + ", Credit: $"
+    + format(credit, ".2f")
+    + ", Balance: $"
+    + format(credit - debit, ".2f")
+)

syntactic-sugar-python/circle.py

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+from math import pi
+
+
+class Circle:
+    def __init__(self, radius):
+        self.radius = radius
+
+    def area(self):
+        return pi * self.radius**2
+
+    def circumference(self):
+        return 2 * pi * self.radius
+
+
+circle = Circle(10)
+print(circle.radius)
+print(circle.area())
+print(circle.circumference())

syntactic-sugar-python/membership.py

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+def is_member(value, iterable):
+    for current_value in iterable:
+        if current_value == value:
+            return True
+    return False
+
+
+print(is_member(5, [1, 2, 3, 4, 5]))
+print(not is_member(5, [1, 2, 3, 4, 5]))
+print(is_member(100, [1, 2, 3, 4, 5]))
+print(not is_member(100, [1, 2, 3, 4, 5]))

syntactic-sugar-python/stack.py

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+class Stack:
+    def __init__(self):
+        self.items = []
+
+    def push(self, item):
+        self.items.append(item)
+
+    def pop(self):
+        return self.items.pop()
+
+    def __iter__(self):
+        yield from self.items
+
+    # def __iter__(self):
+    #     return iter(self.items)
+
+    # def __iter__(self):
+    #     for item in self.items:
+    #         yield item
+
+
+stack = Stack()
+stack.push("one")
+stack.push("two")
+stack.push("three")
+
+for item in stack:
+    print(item)
+
+print(stack.pop())

syntactic-sugar-python/timing.py

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+import functools
+import time
+
+
+def timer(func):
+    @functools.wraps(func)
+    def _timer(*args, **kwargs):
+        start = time.perf_counter()
+        result = func(*args, **kwargs)
+        end = time.perf_counter()
+        print(f"Execution time: {end - start:.4f} seconds")
+        return result
+
+    return _timer
+
+
+@timer
+def delayed_mean(sample):
+    time.sleep(1)
+    return sum(sample) / len(sample)
+
+
+print(delayed_mean([10, 2, 4, 7, 9, 3, 9, 8, 6, 7]))

syntactic-sugar-python/twice.py

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+class Twice:
+    def __init__(self, items):
+        self.items = list(items)
+
+    def __iter__(self):
+        yield from self.items
+        print("Halfway there!")
+        yield from self.items
+
+
+for number in Twice([1, 2, 3]):
+    print(f"-> {number}")

syntactic-sugar-python/user_input.py

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+# With assignment operator
+while (line := input("Type some text: ")) != "stop":
+    print(line)
+
+
+# With assignment before loop
+line = input("Type some text: ")
+
+while line != "stop":
+    print(line)
+    line = input("Type some text: ")
+
+
+# With condition inside loop
+while True:
+    line = input("Type some text: ")
+    if line == "stop":
+        break
+    print(line)