r for reading
r+ opens for reading and writing (cannot truncate a file)
w for writing
w+ for writing and reading (can truncate a file)
rb for reading a binary file. The file pointer is placed at the beginning of the file.
rb+ reading or writing a binary file
wb+ writing a binary file
a+ opens for appending
ab+ Opens a file for both appending and reading in binary. The file pointer is at the end of the file if the file exists. The file opens in the append mode.
x open for exclusive creation, failing if the file already exists (Python 3)# Different modes of text file
"r" = # Open for reading plain text
"w" = # Open for writing plain text
"a" = # Open an existing file for appending plain text
"rb" = # Open for reading binary data
"wb" = # Open for writing binary data