A North Queensland family has saved a toddler from a four-metre-long scrub python after it latched onto the child's arm.

The 22 month-old boy was playing at the family home in Julatten, north of Cairns, with his three-year-old sister when the python struck.

The children's mother and grandparents came to the rescue, stabbing the snake four or five times until it released the boy from its grasp.