model_builder.py

"""
Contains PyTorch model code to instantiate a TinyVGG model.
"""
import torch
from torch import nn


class TrashClassificationCNNModel(nn.Module):
    def __init__(self, input_shape: int, hidden_units: int, output_shape: int):
        super().__init__()
        self.block_1 = nn.Sequential(
            nn.Conv2d(input_shape, hidden_units,
                      kernel_size=3, 
                      stride=1,
                      padding=1),
            nn.ReLU(),
            nn.Conv2d(hidden_units, hidden_units,
                      kernel_size=3, 
                      stride=1,
                      padding=1),
            nn.ReLU(),
            nn.MaxPool2d(kernel_size=2)
        )
        self.block_2 = nn.Sequential(
            nn.Conv2d(hidden_units, hidden_units,
                      kernel_size=3, 
                      stride=1,
                      padding=1),
            nn.ReLU(),
            nn.Conv2d(hidden_units, hidden_units,
                      kernel_size=3, 
                      stride=1,
                      padding=1),
            nn.ReLU(),
            nn.MaxPool2d(kernel_size=2)
        )
        self.classifier = nn.Sequential(
            nn.Flatten(),
            nn.Linear(in_features=hidden_units*28*28,
                      out_features=output_shape)
        )
    
    def forward(self, x):
        x = self.block_1(x)
        x = self.block_2(x)
        x = self.classifier(x)
        return x