Multi-line comprehensions; Python 2/3 compatible; list-comprehensions, generators, dict-comprehensions, and more.

Unroll is a 'vernacular' tool, intended for everyday Python programming.

The most common use-case is the @unroll decorator, for writing the equivalent of multi-line comprehensions:

@unroll(list)
def evens():
    for i in range(5):
        yield 2*i

assert callable(evens)
assert evens() == [0, 2, 4, 6, 8]

The argument into decorator determines the type of comprehension. Use list for a list-comprehension, dict for a dict-comprehension (this works in Python 2.6), and iter for generators (default).

For an even more direct equivalent to multi-line comprehensions, try the @ compr decorator, which immediately invokes the resulting function, resulting in a variable rather than a function:

@compr(list)
def evens():
        for i in range(5):
                yield 2*i

assert isinstance(evens, list)
assert evens == [0, 2, 4, 6, 8]