Documented assumptions and completed docstrings

solutions/get_unique_values.py

@@ -1,7 +1,10 @@
-# Module for extracting unique values from CSV file.
 """
-This module provides the get_unique_values function to extract
-unique values from a specified column in a CSV file.
+This module provides functionality to extract unique values from a CSV file.
+
+It contains the `get_unique_values` function, which takes a file path and
+column name as input and returns a list of unique values from that column.
+The module handles potential errors like invalid file paths or missing column
+names.
 """
 
 import csv
@@ -12,15 +15,20 @@ def get_unique_values(file_path: str, column_name: str) -> list:
     Get unique values from a specified column in a CSV file.
 
     Parameters:
-        file_path (str): Path to the CSV file.
-        column_name (str): Name of the column to extract unique values.
+        file_path (str): Path to the CSV file. It should be a valid path to an existing CSV file.
+                         The function assumes the file is encoded in UTF-8. Both relative and absolute
+                         paths are acceptable. The file must exist, or a FileNotFoundError will be raised.
+        column_name (str): Name of the column to extract unique values. It should correspond to a
+                           header in the CSV file.
 
     Returns:
-        list: Unique values in the specified column.
+        list: Unique values in the specified column. The order of the unique values is not guaranteed to be
+              the same as their order of appearance in the CSV file.
 
     Raises:
-        FileNotFoundError: If the file path is invalid.
+        FileNotFoundError: If the file path is invalid or the file does not exist.
         KeyError: If the column name doesn't exist in the CSV.
+        ValueError: If the `file_path` is an empty string.
 
     Examples:
         >>> with open("test.csv", "w", newline="") as f:
@@ -43,9 +51,15 @@ def get_unique_values(file_path: str, column_name: str) -> list:
         Traceback (most recent call last):
         ...
         FileNotFoundError: File not found: nonexistent_file.csv
+        >>> get_unique_values("", "Name")
+        Traceback (most recent call last):
+        ...
+        ValueError: The file_path cannot be an empty string.
     """
+    if not file_path:
+        raise ValueError("The file_path cannot be an empty string.")
     try:
-        with open(file_path, "r") as file:
+        with open(file_path, "r", encoding="utf-8") as file:
             reader = csv.DictReader(file)
             # Check if the column name exists in the CSV header
             if column_name not in reader.fieldnames: