Merge branch 'revised-solutions-jan2020-update'

Author: somacdivad

ch09-lists-tuples-and-dictionaries/2-lists-are-mutable-sequences.py

@@ -38,3 +38,11 @@
 # Exercise 7
 # Verify that breakfast has three items using len()
 print(len(breakfast) == 3)
+
+
+# Exercise 8
+# Create a new list called `lengths` using a list
+# comprehension that contains the lengths of each
+# string in the `breakfast` list.
+lengths = [len(item) for item in breakfast]
+print(lengths)

ch11-file-input-and-output/1-read-and-write-simple-files.py

@@ -0,0 +1,20 @@
+# 11.2 - Working With File Paths in Python
+# Solutions to review exercises
+
+
+# Exercise 1
+from pathlib import Path
+
+file_path = Path.home() / "my_folder" / "my_file.txt"
+
+
+# Exercise 2
+print(file_path.exists())
+
+
+# Exercise 3
+print(file_path.name)
+
+
+# Exercise 4
+print(file_path.parent.name)

ch11-file-input-and-output/2-working-with-file-paths-in-python.py

@@ -0,0 +1,34 @@
+# 11.3 Common File System Operations
+# Solutions to Exercises
+
+
+# Exercise 1
+from pathlib import Path
+
+new_dir = Path.home() / "my_folder"
+new_dir.mkdir()
+
+
+# Exercise 2
+file1 = new_dir / "file1.txt"
+file2 = new_dir / "file2.txt"
+image1 = new_dir / "image1.png"
+
+file1.touch()
+file2.touch()
+image1.touch()
+
+
+# Exercise 3
+images_dir = new_dir / "images"
+images_dir.mkdir()
+image1.replace(images_dir / "image1.png")
+
+
+# Exercise 4
+file1.unlink()
+
+
+# # Exercise 5
+import shutil
+shutil.rmtree(new_dir)

ch11-file-input-and-output/2-working-with-paths-in-python.py

@@ -0,0 +1,23 @@
+# 11.4 Challenge: Move All Image Files To a New Directory
+# Solution to Challenge
+
+from pathlib import Path
+
+# Change this path to match the location on your computer
+documents_dir = (
+    Path.home() /
+    "python-basics-exercises" /
+    "ch11-file-input-and-output" /
+    "practice_files" /
+    "documents"
+)
+
+# Create an images/ directory in your home directory
+images_dir = Path.home() / "images"
+images_dir.mkdir(exist_ok=True)
+
+# Search for image files in the documents directory and move
+# them to the images/ directory
+for path in documents_dir.rglob("*.*"):
+    if path.suffix.lower() in [".png", ".jpg", ".gif"]:
+        path.replace(images_dir / path.name)

ch11-file-input-and-output/3-challenge-use-pattern-matching-to-delete-files.py

@@ -0,0 +1,25 @@
+# 11.5 - Reading and Writing Files
+# Solutions to Exercises
+
+
+# Exercise 1
+from pathlib import Path
+
+starships = ["Discovery\n", "Enterprise\n", "Defiant\n", "Voyager"]
+
+file_path = Path.home() / "starships.txt"
+with file_path.open(mode="w", encoding="utf-8") as file:
+    file.writelines(starships)
+
+
+# Exercise 2
+with file_path.open(mode="r", encoding="utf-8") as file:
+    for starship in file.readlines():
+        print(starship, end="")
+
+
+# Exercise 3
+with file_path.open(mode="r", encoding="utf-8") as file:
+    for starship in file.readlines():
+        if starship.startswith("D"):
+            print(starship, end="")