This attribute must the specified. It contains an expression that is evaluated when the template is executed and the result is written as a string to the output.
For example:
>>> import albatross >>> ctx = albatross.SimpleContext('.') >>> albatross.Template(ctx, '<magic>', ''' ... hash('spam') is <al-value expr="hash('spam')" whitespace> ... ''').to_html(ctx) >>> ctx.flush_content() hash('spam') is 1626740519