Elegant Python-understanding the file opening Mode

When we use the open () function to open a file, there are several open modes. 'R'-> Read-Only 'W'-> write-only. If the file already exists, it is cleared. If the file does not exist, it is created. 'A'-> append, write to the end of the file 'B'-> binary mode, such as opening an image, audio, or Word file. '+'-> Update (readable and writable) is a bit difficult to understand with the '+' number.

With open('foo.txt ', 'W +') as F: f. Write ('bar \ n') F. Seek (0) Data = f. Read ()

As you can see, the code above can not only be written but also read. Note that you must first locate F. Seek (0). Otherwise, empty data is read. Some may be confused. Since the plus sign is readable and writable, what is the difference between 'W + 'and 'R +. That is, 'W + 'is cleared and will be created(If the object already exists, it is cleared. If the object does not exist, it is created .) 'R + 'is not cleared and is not created