The <al-usearg> tag is used inside a macro definition to define the location where content enclosed by the <al-expand> (5.5.4) tag should be placed when the macro is expanded.
All content enclosed by the <al-expand> tag is passed to the macro as the unnamed argument. The unnamed argument is retrieved in the macro definition by using an <al-usearg> tag without specifying a name (5.5.2.1) attribute. When a macro expects only one argument it is best to use this mechanism.
>>> import albatross >>> ctx = albatross.SimpleContext('.') >>> albatross.Template(ctx, '<magic>', ''' ... <al-macro name="double"> ... 1. <al-usearg> ... 2. <al-usearg> ... </al-macro> ... ''').to_html(ctx) >>> ctx.flush_content() >>> albatross.Template(ctx, '<magic>', ''' ... <al-expand name="double"> ... spam ... </al-expand>''').to_html(ctx) >>> ctx.flush_content() 1. spam 2. spam