A pretty yellow flower, volunteering

I've meant to photograph this plant for some weeks. Everyone who visits our house notices it growing in an half-empty compost bag in the front garden, and comments on how attractive it is. I presume a seed arrived on the wind, or possibly via a bird.

I think I should have waited until the sun was shining on it, possibly when the sun sets, as it is in the shadow of the house for most of the day. The plant has masses of these tiny yellow flowers on its various stems which reach out in an arc from the compost

Doesa anyone recognise it and know its name?

NB I have had a tip from a knowledgable source that this is:
'Ranunculus sceleratus, or Celery-leaved Crowfoot, a British native and quite likely to have come in via a bird. Related to buttercup, so has the potential to become a ‘weed’ in your garden …..  '