Python tricks and patterns

generator.py

# Use the generator .next method to quickly get the first non-None item in a list

if __name__ == "__main__":
    item_list = [None, None, "non-None-A", "non-None-B", None]
    item = next(item for item in item_list if item is not None)
    assert item == "non-None-A"
    print(item)

# -            axes = next(
# -                artist
# -                for artist in [self.cls_obs, self.clsb, self.clb]
# -                if artist is not None
# -            ).axes