File I/O and String Operations Flashcards

Which built-in function is used to open a file in Python?

Answer: open()

The `open()` function opens a file and returns a file object for reading or writing.

What mode string opens a file for writing, creating it if it does not exist and truncating if it does?

Answer: 'w'

Mode `'w'` opens a file for writing, creating it if absent and clearing it if it exists.

What does the `with` statement do when used with `open()`?

Answer: Automatically closes the file when the block exits

The `with` statement is a context manager that ensures the file is closed when the block ends, even on exceptions.

Which method reads the entire file content as a single string?

Answer: read()

`file.read()` reads the entire file and returns it as a single string.

What does `file.readlines()` return?

Answer: A list of strings, one per line

`readlines()` reads all lines and returns them as a list of strings including newline characters.

Which file mode opens a file for appending without truncating existing content?

Answer: 'a'

Mode `'a'` opens a file for appending; writes go to the end without erasing existing data.