All keys matched successfully missing when loading state dict on optimizers

[bobiblazeski]

🐛 Bug

To Reproduce

Steps to reproduce the behavior:

1. Create a model
2. Save model
3. load model state dictionary
4. Message appears
5. Create optimizer
6. Save optimizer
7. load optimizer state dictionary
8. The message is missing

import torch 
import torchvision.models as models

alexnet = models.alexnet()
torch.save(alexnet.state_dict(), './alexnet.pth')
alexnet.load_state_dict(torch.load('./alexnet.pth'))
# <All keys matched successfully>
adam = torch.optim.Adam(alexnet.parameters())
torch.save(adam.state_dict(), './adam.pth')
adam.load_state_dict(torch.load('./adam.pth'))

Expected behavior

The message should be printed when optimizer state is loaded

It would be nice if load_state_dict is consistent for both models and optimizers

Environment

Collecting environment information...
PyTorch version: 1.5.0+cu101
Is debug build: No
CUDA used to build PyTorch: 10.1

OS: Ubuntu 20.04 LTS
GCC version: (Ubuntu 8.4.0-3ubuntu2) 8.4.0
CMake version: version 3.17.2

Python version: 3.8
Is CUDA available: Yes
CUDA runtime version: 10.1.105
GPU models and configuration: GPU 0: GeForce RTX 2070
Nvidia driver version: 440.64
cuDNN version: /usr/lib/x86_64-linux-gnu/libcudnn.so.7.6.4

Versions of relevant libraries:
[pip3] numpy==1.18.3
[pip3] torch==1.5.0+cu101
[pip3] torchvision==0.6.0+cu101
[conda] Could not collect

Additional context

cc @vincentqb

[VitalyFedyunin]

Up to Optimizers maintainers to consider if we want it, as original way of printing 'message' via __repr__ is questionable

pytorch/torch/nn/modules/module.py

Line 11 in 3569c59

def __repr__(self):

[ssnl]

The original does not print the message. Rather it returns an object that represents the loading result, which has different attrs. It looks like printing only in interactive environments.