Merge branch 'master' into python-unittest

Author: lpozo

formatting_floats_f_strings/Code_and_Solutions.ipynb

@@ -0,0 +1,11 @@
+# How to Format Floats Within F-Strings in Python
+
+These materials are for use with the Real Python tutorial [How to Format Floats Within F-Strings in Python](https://realpython.com/how-to-python-f-string-format-float/)
+
+The code plus exercise solutions are all presented inside the `Code_and_Solutions.ipynb` Jupyter Notebook.
+
+To view the file, you will need to install either [Jupyter Notebook](https://realpython.com/jupyter-notebook-introduction/) or [JupyterLab](https://realpython.com/using-jupyterlab/).
+
+**Note:** Some minor differences exist between the code presented in the tutorial and those in the Jupyter Notebook. This is necessary to align the output of the notebook with those in the standard Python REPL used to produce the tutorial.
+
+You should also run Python 3.12 or later.

formatting_floats_f_strings/README.md

@@ -0,0 +1,3 @@
+# What's Lazy Evaluation in Python?
+
+A summary of the code used in the [What's Lazy Evaluation in Python?](https://realpython.com/python-lazy-evaluation/) tutorial on Real Python.

python-lazy-evaluation/README.md

@@ -0,0 +1,24 @@
+"""
+Exploring the itertools module
+"""
+
+import itertools
+import sys
+
+# Explore itertools.chain()
+first_team = ["Sarah", "Matt", "Jim", "Denise", "Kate"]
+second_team = ["Mark", "Zara", "Mo", "Jennifer", "Owen"]
+
+for name in itertools.chain(first_team, second_team):
+    print(name)
+
+# Verify changes in reference counts
+print(sys.getrefcount(first_team))
+
+quiz_team = itertools.chain(first_team, second_team)
+print(sys.getrefcount(first_team))
+
+for name in quiz_team:
+    print(name)
+
+print(sys.getrefcount(first_team))

python-lazy-evaluation/exploring_itertools_chain.py

@@ -0,0 +1,22 @@
+"""
+Exploring the itertools module
+"""
+
+import itertools
+
+numbers = [2, 4, 6, 8, 10]
+standard_slice = numbers[1:4]
+iterator_slice = itertools.islice(numbers, 1, 4)
+
+# Change third element in numbers
+numbers[2] = 999
+
+print(numbers)
+
+print("\nStandard slice:")
+for number in standard_slice:
+    print(number)
+
+print("\nIterator slice:")
+for number in iterator_slice:
+    print(number)

python-lazy-evaluation/exploring_itertools_islice.py

@@ -0,0 +1,37 @@
+"""
+Exploring generator expressions
+"""
+
+import random
+
+# List comprehension
+coin_toss = ["Heads" if random.random() > 0.5 else "Tails" for _ in range(10)]
+
+print(f"List comprehension:\n{coin_toss}")
+
+# Generator expression
+coin_toss = ("Heads" if random.random() > 0.5 else "Tails" for _ in range(10))
+print(f"\nGenerator expression:\n{coin_toss}")
+
+print(f"\nFirst coin toss: {next(coin_toss)}")
+print(f"Second coin toss: {next(coin_toss)}")
+
+# Print remaining coin tosses
+for toss_result in coin_toss:
+    print(toss_result)
+
+# Defining a generator function
+
+
+def generate_coin_toss(number):
+    for _ in range(number):
+        yield "Heads" if random.random() > 0.5 else "Tails"
+
+
+coin_toss = generate_coin_toss(10)
+print("\nUsing a generator function:")
+print(next(coin_toss))
+print(next(coin_toss))
+
+for toss_result in coin_toss:
+    print(toss_result)

python-lazy-evaluation/generator_expressions.py

@@ -0,0 +1,36 @@
+"""
+Creating an infinite sequence of elements using generators
+"""
+
+import itertools
+
+quarters = itertools.count(start=0, step=0.25)
+# Print the first 8 elements, however, the sequence is infinite
+for _ in range(8):
+    print(next(quarters))
+
+names = ["Sarah", "Matt", "Jim", "Denise", "Kate"]
+rota = itertools.cycle(names)
+print(rota)
+
+print(next(rota))
+print(next(rota))
+print(next(rota))
+
+
+# Use a generator function
+def generate_rota(iterable):
+    index = 0
+    length = len(iterable)
+    while True:
+        yield iterable[index]
+        if index == length - 1:
+            index = 0
+        else:
+            index += 1
+
+
+rota = generate_rota(names)
+print("\nUsing a generator function")
+for _ in range(12):
+    print(next(rota))

python-lazy-evaluation/infinite_elements.py

@@ -0,0 +1,24 @@
+"""
+Eager and lazy options for reading a CSV file
+"""
+
+import csv
+import pprint
+
+print("Eager evaluation using 'open()'")
+with open("superhero_pets.csv", encoding="utf-8") as file:
+    data = file.readlines()
+
+pprint.pprint(data)
+
+print("\nLazy evaluation using 'csv.reader()'")
+with open("superhero_pets.csv", encoding="utf-8", newline="") as file:
+    data = csv.reader(file)
+    print(data)
+
+    print(next(data))
+    print(next(data))
+    print(next(data))
+
+    for row in data:
+        print(row)

python-lazy-evaluation/reading_csv_file.py

@@ -0,0 +1,6 @@
+Pet Name,Species,Superpower,Favorite Snack,Hero Owner
+Whiskertron,Cat,Teleportation,Tuna,Catwoman
+Flashpaw,Dog,Super Speed,Peanut Butter,The Flash
+Mystique,Squirrel,Illusion,Nuts,Doctor Strange
+Quackstorm,Duck,Weather Control,Bread crumbs,Storm
+Bark Knight,Dog,Darkness Manipulation,Bacon,Batman

python-lazy-evaluation/superhero_pets.csv

@@ -0,0 +1,25 @@
+"""
+Exploring 'enumerate()' lazy evaluation
+"""
+
+import random
+
+names = ["Sarah", "Matt", "Jim", "Denise", "Kate"]
+random.shuffle(names)
+print(names)
+
+# Using `enumerate()` in a 'for' loop
+for index, name in enumerate(names, start=1):
+    print(f"{index}. {name}")
+
+# Using `enumerate()` with 'next()'
+numbered_names = enumerate(names, start=1)
+print(numbered_names)
+
+print(next(numbered_names))
+print(next(numbered_names))
+
+# Update third name
+names[2] = "The Coffee Robot"
+print(next(numbered_names))
+# Output: (3, 'The Coffee Robot')