Question

How many file modes can be used with the open() function to open a file? State the function of each mode.

Answer 1

The main access modes are:

Mode	Function
r	Opens a text file for reading; the file must exist.
rb	Opens a binary file for reading.
w	Opens a text file for writing; creates a new file or overwrites an existing one.
wb	Opens a binary file for writing; creates or overwrites the file.
a	Opens a text file for appending at the end; creates it if necessary.
ab	Opens a binary file for appending.
r+	Opens a text file for both reading and writing; the file must exist.
rb+	Opens a binary file for both reading and writing.
w+	Opens a text file for reading and writing; overwrites or creates the file.
wb+	Opens a binary file for reading and writing; overwrites or creates it.
a+	Opens a text file for reading and appending.
ab+	Opens a binary file for reading and appending.

The b indicates binary mode and + indicates both reading and writing.