Added a Python script to calculate or verify a file’s checksum/hash/message digest (MD5, SHA-1, SHA-256, etc.) to my public code repository of miscellaneous stuff.
The Python section of that repo has a subfolder for this little utility,
in which you find the files
checksum.py (the command line version of it) and
gui.pyw (a simple Tkinter-based GUI).
There is also a nice little ReadMe now for it, with a few examples (and screenshots) on how to use it; so I will not repeat the details here.