The expr attribute specifies an expression that yields a sequence that the iterator specified in the iter (5.3.8.5) attribute will iterate over. All of the enclosed content is then evaluated for each element in the sequence.
For example:
>>> import albatross >>> ctx = albatross.SimpleContext('.') >>> albatross.Template(ctx, '<magic>', ''' ... <al-for iter="i" expr="range(15)" whitespace="indent"> ... <al-value expr="i.value()"> ... </al-for whitespace> ... ''').to_html(ctx) >>> ctx.flush_content() 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14