cnn_model.py

class MyModel(nn.Module):
    def __init__(self):
        super(MyModel, self).__init__()

        # 28x28x1 => 26x26x32
        self.conv1 = nn.Conv2d(in_channels=1, out_channels=32, kernel_size=3)
        self.d1 = nn.Linear(26 * 26 * 32, 128)
        self.d2 = nn.Linear(128, 10)

    def forward(self, x):
        # 32x1x28x28 => 32x32x26x26
        x = self.conv1(x)
        x = F.relu(x)

        # flatten => 32 x (32*26*26)
        x = x.flatten(start_dim = 1)

        # 32 x (32*26*26) => 32x128
        x = self.d1(x)
        x = F.relu(x)

        # logits => 32x10
        logits = self.d2(x)
        out = F.softmax(logits, dim=1)
        return out