Python embedded block stops working after consume()

Hi,

I've been trying to implement a sync python embedded block that processes all input_items. At the end of the work() function, I call 

output_items[0][:] = input_items[0]

self.consume_each(len(input_items[0]))

return len(input_items[0])

This works well the first time and all data is processed correctly, but then, the block stops working, i.e., it doesn't process any new upcoming data and input_items[0] is always filled with zeros.

I hope someone could help me with this.

Thanks in advance.

Best regards,
Verónica