TypeError: 'float' object is not iterable

[gongshuai0606]

Hi, there is an error "TypeError: 'float' object is not iterable" in line 50 bias =','.join(map(str,lp.bias[i].data.tolist())) of vde_metadynamics/vde_metadynamics/render_network.py when I run the ala_res.ipynb of vde_metadynamics/examples/alanine. When I print out the bias[i].data.tolist(), it's a value 0.31510797142982483.