TypeError: validation_step() missing 1 required positional argument: 'dataloader_nb'

[MooreManor]

def validation_step(self, batch, batch_nb, dataloader_nb, vis=False, save=True, mesh_save_dir=None):

My pytorch-lightning version is 1.6.0, but the code is written with pytorch-lightning 1.1.8. And when I ran the code, I met the bug validation_step() missing 1 required positional argument: 'dataloader_nb'.

How can I fix it and pass parameters to validation_step() ?

[rohitgr7]

if you are using a single val dataloader:

def validation_step(self, batch, batch_idx):

if you are using multiple val dataloader:

def validation_step(self, batch, batch_idx, dataloader_idx):

for consistency, you can just do

def validation_step(self, batch, batch_idx, dataloader_idx=0):