Any way to suppress key errors when a dictionary key is not found in Chameleon ZPT templates?

Question

Sometimes it would be nice to be able to do this, just return None in any expression evaluating for a nonexistent dict key instead of raising KeyError.

Answer 1

You'd use dict.get() to access the key instead:

<div tal:attributes="class some_dict.get(some_key)">

where the class attribute would be omitted if some_key is not present, as the default return value from dict.get() is None if the key is missing.