Reading text files safely

Learning objectives

• Open a text file for reading with a with statement.
• Recognize that file operations can fail and need handling.

Use a context manager

with open("notes.txt", "r", encoding="utf-8") as file:
    text = file.read()
print(text)

open returns a file object. The with statement establishes a context that closes it when the indented block ends. Specifying UTF-8 makes the expected text encoding clear.

Failure modes and practice

The path may not exist, permissions may deny access, or the bytes may not match the chosen encoding. Programs that interact with real files should decide which exceptions to catch and what a user should see instead of silently losing an error.

Common mistakes and references

• Do not overwrite a file by using write mode when your intent is to read.
• Do not assume a relative path means the same thing in every execution environment.

• Python tutorial: reading and writing files
• Python documentation: open