IfElse¶
If-else conditional control flow aka conditional computation.
This node evaluates what is wired into its "then" branch if the condition was true, and what is wired into the "else" branch if the condition was false. This is called the "taken" branch. Crucially, the non-taken branch is not evaluated (i.e., the nodes do not run). This uses Python conditional evaluation, meaning that an empty list ([]), empty dictionary ({}), empty string (''), or zero value (0 or 0.0) will evaluate to False. If the taken branch has nothing wired into it, then the output defaults to None. If nothing is wired into the condition port or if it receives a None, then the else branch is evaluated and its value returned. Version 1.0.1
Ports/Properties¶
condition¶
Input condition.
then_branch¶
Then branch. Executed if condition is true.
else_branch¶
Else branch. Executed if condition is false.
result¶
Result of the branch that was evaluated.
emit_resets¶
Emit signal reset notifications when the condition changes. This can be used if the IfElse node controls codepaths through which signals flow and where downstream nodes should reset themselves upon a change of the condition. However, in rare cases this can lead to unexpected behavior: namely, if an IfElse in a machine-learning pipeline is driven by an is_training flag, it will cause a reset when the training flag changes, which leads to a reset of trainable state on the test set (unless the nodes are marked as do not reset model), which then causes retraining on the test set, which is likely a bug (that can give spuriously better results). For this reason, this flag is turned off by default, but it may be enabled if needed.
set_breakpoint¶
Set a breakpoint on this node. If this is enabled, your debugger (if one is attached) will trigger a breakpoint.
metadata¶
User-definable meta-data associated with the node. Usually reserved for technical purposes.