I have been reading the thread "while expression feature proposal," and one of the interesting outcomes of the thread is the idea that Python could allow you to attach names to subexpressions, much like C allows. In C you can say something like this:
tax_next_year = (new_salary = salary * (1 + raise)) * tax_rate To avoid the "=" pitfall, folks have proposed something like this for Python: tax_next_year = ((salary * (1 + raise)) as new_salary) * tax_rate print new_salary, tax_next_year The basic rule in Python is that you can only do one assignment per line of code, which generally forces you to write more readable code IMHO: new_salary = salary * (1 + raise) tax_next_year = new_salary * tax_rate print new_salary, tax_next_year The above code is slightly more verbose than the "as" proposal would permit, but the latter code is arguably easier for a human to parse, and it's also very amenable to print debugging and/or defensive coding: new_salary = salary * (1 + raise) print new_salary assert new_salary > salary tax_next_year = new_salary * tax_rate print new_salary, tax_next_year If the problem statement is "How do I name subexpression?", then Python already has a clear path--break your code up into multiple lines. I'm wondering where this simple solution really breaks down from a readability perspective. Perhaps with short-circuited boolean expressions? -- http://mail.python.org/mailman/listinfo/python-list
