Read Text Safely

A path answers “which file?” The next questions are “what kind of access?” and “how should these bytes become text?”

Here is the complete boundary this lesson builds:

with open(path, "r", encoding="utf-8") as handle:
    # read from handle here

Read that first line from the inside out:

• path is the file to open;

• "r" means read mode;

• encoding="utf-8" says how stored bytes become Python strings;

• as handle gives the open file a temporary name.

Why with owns the handle

An open file is an operating-system resource. It should be closed when the work is finished, including when reading fails halfway through.

The with statement makes that lifetime visible. Python opens the file before entering the indented block and closes it when the block ends. It also closes the file when an exception leaves the block early. You do not need a distant handle.close() that a new return or error can accidentally skip.

This is a context manager: the value produced by open(...) knows how to enter and leave a managed block safely. You will meet other context managers later. For now, the durable rule is small: when a file handle belongs to one operation, put that operation inside with.

Read lines without keeping empty records

data/books.txt contains one title per line and one deliberate blank line. Iterating over the handle gives you each line as text, including its final newline. .strip() removes that surrounding whitespace. An empty result should not become an empty book title.

Build the result with the list and loop tools you already know:

books = []
for line in handle:
    title = line.strip()
    if title:
        books.append(title)

Use the path parameter, not BOOKS_PATH. It is tempting to reach for the constant you can see at the top of the file, but a function that only reads one particular file is not reusable, and the next chapters will hand this one several different files. Write it so it reads whatever it is given.

Encoding is part of the file contract

UTF-8 can represent the non-ASCII title Cien años de soledad and ordinary English text in one portable encoding. Relying on a machine default leaves the same bytes open to different interpretations on different computers.

encoding="utf-8" is not error recovery. It is an explicit agreement. If a file’s bytes are not valid UTF-8, Python will raise UnicodeDecodeError; the next lesson decides where that expected boundary failure belongs.

Complete read_books(path) in the project editor, then submit.

If you get stuck on the loop, ask Monty what line.strip() returns for a line that contains only a newline. That single value explains why the blank line needs handling at all.