# How to detect if a vse strip is used in conjunction with an effect strip with python?

Moving strips which are used in conjunction with an effect strips will cause errors if moved(with python) without the effect strips, and most of the effect strips can't themselves be moved because their frame_final_start/end values can't be set. So I need to detect if a strip(ex. movie) is used in conjunction with an effect strip ex. as part of a cross dissolve. How do I do that?

All effect strips that have locked frame values have the 'input_1' attribute (which is set to another strip), so detecting a strip of this type is as simple as:

if hasattr(strip, 'input_1'):


You can also check for transition effects by looking for 'input_2' in the same way.