Why are underscores better than hyphens for file names?
The issue here is that importing files with the hyphen-minus (the default keyboard key -; U+002D) in their name doesn't work since it represents minus signs in Python. So, if you had your own module you wanted to import, it shouldn't have a hyphen in its name:
>>> import test-1 File "<stdin>", line 1 import test-1 ^SyntaxError: invalid syntax>>> import test_1>>>Larger programs tend to be logically separated into many different modules, hence the quote
the name with the hyphen limits our ability to write larger and more sophisticated programs.