Merge pull request #405 from realpython/python-list

Sample code for the Python `list` article

Author: KateFinegan

python-list/README.md

@@ -0,0 +1,3 @@
+# Python's list Data Type: A Deep Dive With Examples
+
+This folder provides the code examples for the Real Python tutorial [Python's `list` Data Type: A Deep Dive With Examples](https://realpython.com/python-list/).

python-list/chunks.py

@@ -0,0 +1,6 @@
+def split_list(list_object, chunk_size):
+    chunks = []
+    for start in range(0, len(list_object), chunk_size):
+        stop = start + chunk_size
+        chunks.append(list_object[start:stop])
+    return chunks

python-list/employee.py

@@ -0,0 +1,10 @@
+employees = [
+    ("John", 30, "Designer", 75000),
+    ("Jane", 28, "Engineer", 60000),
+    ("Bob", 35, "Analyst", 50000),
+    ("Mary", 25, "Service", 40000),
+    ("Tom", 40, "Director", 90000),
+]
+
+
+sorted_employees = sorted(employees, key=lambda e: e[1])

python-list/fibonacci.py

@@ -0,0 +1,6 @@
+def fibonacci_generator(stop):
+    current_fib, next_fib = 0, 1
+    for _ in range(0, stop):
+        fib_number = current_fib
+        current_fib, next_fib = next_fib, current_fib + next_fib
+        yield fib_number

python-list/grades.py

@@ -0,0 +1,39 @@
+class GradeList(list):
+    def __init__(self, grades):
+        grades = [self._validate(grade) for grade in grades]
+        super().__init__(grades)
+
+    def __setitem__(self, index, grade):
+        if isinstance(index, slice):
+            start, stop, step = index.indices(len(self))
+            grades = [self._validate(grade) for grade in grade]
+            return super().__setitem__(slice(start, stop, step), grades)
+        super().__setitem__(index, self._validate(grade))
+
+    def __add__(self, grades):
+        grades = [self._validate(grade) for grade in grades]
+        grades = super().__add__(grades)
+        return self.__class__(grades)
+
+    __radd__ = __add__
+
+    def __iadd__(self, grades):
+        grades = [self._validate(grade) for grade in grades]
+        return super().__iadd__(grades)
+
+    def append(self, grade):
+        return super().append(self._validate(grade))
+
+    def extend(self, grades):
+        grades = [self._validate(grade) for grade in grades]
+        return super().extend(grades)
+
+    def average(self):
+        return sum(self) / len(self)
+
+    def _validate(self, value):
+        if not isinstance(value, (int, float)):
+            raise TypeError("grades must be numeric")
+        if not (0 <= value <= 100):
+            raise ValueError("grade must be between 0 and 100")
+        return value

python-list/matrix.py

@@ -0,0 +1,9 @@
+matrix = []
+for row in range(5):
+    matrix.append([])
+    for _ in range(5):
+        matrix[row].append(0)
+
+matrix = [[0 for _ in range(5)] for _ in range(5)]
+
+matrix = [[0] * 5 for _ in range(5)]

python-list/median.py

@@ -0,0 +1,10 @@
+def median(sample):
+    n = len(sample)
+    index = n // 2
+    sorted_sample = sorted(sample)
+    # Odd number of values
+    if n % 2 != 0:
+        return sorted_sample[index]
+    # Even number of values
+    lower, upper = index - 1, index + 1
+    return sum(sorted_sample[lower:upper]) / 2

python-list/repeated.py

@@ -0,0 +1,6 @@
+def get_unique_items(list_object):
+    result = []
+    for item in list_object:
+        if item not in result:
+            result.append(item)
+    return result