That's not how it works.

There should be a single return.

oh sry, I did it because of
#6609 (comment)

But now I see what you mean. I'll change that

f254a95 is not what I meant. I meant to keep a single
return Klass(.. to keep the logic we wrote in #6636. The entire purpose of #6636 was to keep this one simple.

Maybe I'm missing something. I'll give it a shot.

Actually I already wrote it for you here #6609 (comment)

But I think that e41236f is even cleaner.

Actually I already wrote it for you here #6609 (comment)

Yes, it just seemed to me that you'd be most in favor of:

+                stc = VectorSourceEstimate(
+                    data=(data_rot, sens_data), vertices=vertices, tmin=tmin,
+                    tstep=tstep, subject=subject
+                )
+            else:
+                stc = VectorSourceEstimate(
+                    data=data_rot, vertices=vertices, tmin=tmin,
+                    tstep=tstep, subject=subject
+                )

But anyhow, I like your solution with the sentinel (tbh I didn't know about that practice). But it gets rid of that is_kernel bool and it's compact. So, for me, that's fine!

@massich

The code is meant to read by people (machines executing it is secondary), and usually, the flow is: look at the definition, look at the return check whatever else afterward. If you have 2 returns or you construct the return in 2 different places (which is the same thing) I need to understand what's in the middle of the function. Most of the time when you read a function it is not for debugging purposes I just want to skim through it and get a good grasp of whats going on.

If I have a single place that returns Klass and does something at data and this is in the return, I need no further reading. This function is a factory. Based on whatever, chooses which class to construct and modifies the data accordingly.

@DiGyt this is a nice read on sentinel https://treyhunner.com/2019/03/unique-and-sentinel-values-in-python/