i already did that
train_tfms =tt.Compose([tt.Compose([
tt.Resize(256),
tt.CenterCrop(224),
tt.ToTensor(),
tt.Normalize(mean=0.1817, std=0.1797)
])])
valid_tfms=tt.Compose([tt.Compose([
tt.Resize(256),
tt.CenterCrop(224),
tt.ToTensor(),
tt.Normalize(mean=0.1817, std=0.1797)
])])