Solution

app/create_file.py

@@ -1 +1,75 @@
-# write your code here
+import os
+import sys
+from datetime import datetime
+
+
+def parse_args(args: list[str]) -> tuple[list[str], str | None]:
+    directories: list[str] = []
+    filename: str | None = None
+    index = 0
+
+    while index < len(args):
+        token = args[index]
+
+        if token == "-d":
+            index += 1
+            while index < len(args) and not args[index].startswith("-"):
+                directories.append(args[index])
+                index += 1
+            continue
+
+        if token == "-f":
+            index += 1
+            if index < len(args):
+                filename = args[index]
+                index += 1
+            continue
+
+        index += 1
+
+    return directories, filename
+
+
+def get_content_lines() -> list[str]:
+    lines: list[str] = []
+    while True:
+        content_line = input("Enter content line: ")
+        if content_line == "stop":
+            break
+        lines.append(content_line)
+    return lines
+
+
+def write_content(file_path: str, lines: list[str]) -> None:
+    timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+    numbered_lines = [
+        f"{index} {line}"
+        for index, line in enumerate(lines, start=1)
+    ]
+    content_block = "\n".join([timestamp, *numbered_lines])
+
+    if os.path.exists(file_path) and os.path.getsize(file_path) > 0:
+        with open(file_path, "a", encoding="utf-8") as file:
+            file.write("\n\n" + content_block)
+    else:
+        with open(file_path, "w", encoding="utf-8") as file:
+            file.write(content_block)
+
+
+def main() -> None:
+    directories, filename = parse_args(sys.argv[1:])
+
+    target_dir = os.path.join(*directories) if directories else "."
+    if directories:
+        os.makedirs(target_dir, exist_ok=True)
+
+    if filename is None:
+        return
+
+    file_path = os.path.join(target_dir, filename)
+    content_lines = get_content_lines()
+    write_content(file_path, content_lines)
+
+
+if __name__ == "__main__":
+    main()

tests/test_main.py

@@ -4,6 +4,8 @@
 from datetime import datetime
 from unittest.mock import patch
 
+BASE_DIR = os.path.dirname(os.path.dirname(__file__))
+SCRIPT_PATH = os.path.join(BASE_DIR, "app", "create_file.py")
 
 def cleanup() -> None:
     for item in ["dir1", "file.txt"]:
@@ -12,170 +14,110 @@ def cleanup() -> None:
         elif os.path.isfile(item):
             os.remove(item)
 
-
 def test_create_dir_and_file() -> None:
     cleanup()
-    test_args = ["app/create_file.py", "-d", "dir1", "dir2", "-f", "file.txt"]
+    test_args = [SCRIPT_PATH, "-d", "dir1", "dir2", "-f", "file.txt"]
     test_input = ["Line1 content", "Line2 content", "stop"]
 
     with patch("sys.argv", test_args), patch("builtins.input", side_effect=test_input):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
     path = os.path.join("dir1", "dir2", "file.txt")
-    assert os.path.exists(path), (
-        f"File {path} should exist in the created directory hierarchy"
-    )
+    assert os.path.exists(path)
 
     with open(path, "r") as source_file:
         lines = source_file.readlines()
-        # Verify timestamp format
         try:
             datetime.strptime(lines[0].strip(), "%Y-%m-%d %H:%M:%S")
         except ValueError:
-            assert False, (
-                f"Invalid timestamp format: '{lines[0].strip()}'. "
-                f"Expected format: YYYY-MM-DD HH:MM:SS"
-            )
-
-        assert lines[1].strip() == "1 Line1 content", (
-            f"Line 1 mismatch: expected '1 Line1 content', got '{lines[1].strip()}'"
-        )
-        assert lines[2].strip() == "2 Line2 content", (
-            f"Line 2 mismatch: expected '2 Line2 content', got '{lines[2].strip()}'"
-        )
-    cleanup()
+            assert False
 
+        assert lines[1].strip() == "1 Line1 content"
+        assert lines[2].strip() == "2 Line2 content"
+    cleanup()
 
 def test_create_file_and_dirs_reversed() -> None:
     cleanup()
-    test_args = [
-        "app/create_file.py",
-        "-f",
-        "file.txt",
-        "-d",
-        "dir1",
-        "dir2",
-        "dir3",
-        "dir4",
-    ]
+    test_args = [SCRIPT_PATH, "-f", "file.txt", "-d", "dir1", "dir2", "dir3", "dir4"]
     test_input = ["Line1", "stop"]
 
     with patch("sys.argv", test_args), patch("builtins.input", side_effect=test_input):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
     path = os.path.join("dir1", "dir2", "dir3", "dir4", "file.txt")
-    assert os.path.exists(path), (
-        f"File {path} should be created even when -f flag is passed before -d"
-    )
+    assert os.path.exists(path)
     cleanup()
 
-
 def test_create_only_file() -> None:
     cleanup()
-    test_args = ["app/create_file.py", "-f", "file.txt"]
+    test_args = [SCRIPT_PATH, "-f", "file.txt"]
     test_input = ["Content line", "stop"]
 
     with patch("sys.argv", test_args), patch("builtins.input", side_effect=test_input):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
-    assert os.path.exists("file.txt"), (
-        "File 'file.txt' should be created in the current directory "
-        "when no directories are specified"
-    )
+    assert os.path.exists("file.txt")
     cleanup()
 
-
 def test_create_only_dirs() -> None:
     cleanup()
-    test_args = ["app/create_file.py", "-d", "dir1", "dir2", "dir3", "dir4"]
+    test_args = [SCRIPT_PATH, "-d", "dir1", "dir2", "dir3", "dir4"]
 
     with patch("sys.argv", test_args):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
     path = os.path.join("dir1", "dir2", "dir3", "dir4")
-    assert os.path.isdir(path), (
-        f"Directory {path} should be created when only -d flag is provided"
-    )
+    assert os.path.isdir(path)
     cleanup()
 
-
 def test_append_with_blank_line() -> None:
     cleanup()
-    # First entry
     with (
-        patch("sys.argv", ["app/create_file.py", "-f", "file.txt"]),
+        patch("sys.argv", [SCRIPT_PATH, "-f", "file.txt"]),
         patch("builtins.input", side_effect=["Line 1", "stop"]),
     ):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
-    # Second entry
     with (
-        patch("sys.argv", ["app/create_file.py", "-f", "file.txt"]),
+        patch("sys.argv", [SCRIPT_PATH, "-f", "file.txt"]),
         patch("builtins.input", side_effect=["Line 2", "stop"]),
     ):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
     with open("file.txt", "r") as source_file:
         content = source_file.read()
 
-    # Check for blank line between entries
     parts = content.split("\n\n")
-    assert len(parts) == 2, (
-        f"Expected exactly 2 entries separated by a blank line, but found {len(parts)}"
-    )
-
-    # Check first entry
-    lines1 = parts[0].split("\n")
-    assert lines1[1] == "1 Line 1", (
-        f"First entry content mismatch: expected '1 Line 1', got '{lines1[1]}'"
-    )
-
-    # Check second entry
-    lines2 = parts[1].split("\n")
-    assert lines2[1] == "1 Line 2", (
-        f"Second entry content mismatch: expected '1 Line 2', got '{lines2[1]}'"
-    )
+    assert len(parts) == 2
+    assert "1 Line 1" in parts[0]
+    assert "1 Line 2" in parts[1]
     cleanup()
 
-
 def test_stop_word() -> None:
     cleanup()
-    # Test that it stops exactly at "stop"
-    test_args = ["app/create_file.py", "-f", "file.txt"]
+    test_args = [SCRIPT_PATH, "-f", "file.txt"]
     test_input = ["line", "stop", "extra"]
 
     with patch("sys.argv", test_args), patch("builtins.input", side_effect=test_input):
-        runpy.run_path("app/create_file.py")
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
 
     with open("file.txt", "r") as source_file:
         lines = source_file.readlines()
-        assert len(lines) == 2, (
-            "File should contain exactly 2 lines "
-            "(timestamp and 1 content line), "
-            f"but has {len(lines)}"
-        )
-        assert lines[1].strip() == "1 line", (
-            f"Content line mismatch: expected '1 line', got '{lines[1].strip()}'"
-        )
+        assert len(lines) == 2
+        assert lines[1].strip() == "1 line"
     cleanup()
 
-
 def test_input_prompt() -> None:
     cleanup()
-    test_args = ["app/create_file.py", "-f", "file.txt"]
+    test_args = [SCRIPT_PATH, "-f", "file.txt"]
     test_input = ["line 1", "stop"]
 
     with (
         patch("sys.argv", test_args),
         patch("builtins.input", side_effect=test_input) as mock_input,
     ):
-        runpy.run_path("app/create_file.py")
-
-        assert mock_input.call_args_list[0][0][0] == "Enter content line: ", (
-            f"Expected prompt 'Enter content line: ', but got '{mock_input.call_args_list[0][0][0]}'"
-        )
-        assert mock_input.call_args_list[1][0][0] == "Enter content line: ", (
-            f"Expected prompt 'Enter content line: ' for the stop command as well, "
-            f"but got '{mock_input.call_args_list[1][0][0]}'"
-        )
-    cleanup()
+        runpy.run_path(SCRIPT_PATH, run_name="__main__")
+
+        assert mock_input.call_args_list[0][0][0] == "Enter content line: "
+        assert mock_input.call_args_list[1][0][0] == "Enter content line: "
+    cleanup()