File Modes:

• r : read
• r+ : reading and writing (cannot truncate file)
• rb : for reading a binary file
• rb+ : reading or writing a binary file
• w : for writing, create if doesn't exist
• w+ : for writing and reading (can truncate file)
• wb+ : for writing or reading a binary file
• a : open a file for appending (will create if it doesn't exist)
• a+ : open a file for appending and reading
• ab+ : open a binary file for appending or reading
• x : open for exclusive creation (Python 3). Raises FileExistsError if file exists.

References:

1. https://stackoverflow.com/a/16212401