import os
import json
import torch
import torch.nn as nn
from torchvision import transforms, datasets
import torch.optim as optim
from tqdm import tqdm
from model import vgg
def main():

device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")print("using {} device.".format(device))data_transform = {    "train": transforms.Compose([transforms.RandomResizedCrop(224),                                 transforms.RandomHorizontalFlip(),                                 transforms.ToTensor(),                                 transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))]),    "val": transforms.Compose([transforms.Resize((224, 224)),                               transforms.ToTensor(),                               transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])}data_root = os.path.abspath(os.path.join(os.getcwd(), "../.."))  # get data root pathimage_path = os.path.join(data_root, "data_set", "flower_data")  # flower data set pathassert os.path.exists(image_path), "{} path does not exist.".format(image_path)train_dataset = datasets.ImageFolder(root=os.path.join(image_path, "train"),                                     transform=data_transform["train"])train_num = len(train_dataset)# {'daisy':0, 'dandelion':1, 'roses':2, 'sunflower':3, 'tulips':4}flower_list = train_dataset.class_to_idxcla_dict = dict((val, key) for key, val in flower_list.items())# write dict into json filejson_str = json.dumps(cla_dict, indent=4)with open('class_indices.json', 'w') as json_file:    json_file.write(json_str)batch_size =32nw = min([os.cpu_count(), batch_size if batch_size > 1 else 0, 8])  # number of workersprint('Using {} dataloader workers every process'.format(nw))train_loader = torch.utils.data.DataLoader(train_dataset,                                           batch_size=batch_size, shuffle=True,                                           num_workers=0)validate_dataset = datasets.ImageFolder(root=os.path.join(image_path, "val"),                                        transform=data_transform["val"])val_num = len(validate_dataset)validate_loader = torch.utils.data.DataLoader(validate_dataset,                                              batch_size=batch_size, shuffle=False,                                              num_workers=0)print("using {} images for training, {} images for validation.".format(train_num,

val_num))

# test_data_iter = iter(validate_loader)# test_image, test_label = test_data_iter.next()model_name = "vgg16"net = vgg(model_name=model_name, num_classes=5, init_weights=True)net.to(device)loss_function = nn.CrossEntropyLoss()optimizer = optim.Adam(net.parameters(), lr=0.0001)epochs = 30best_acc = 0.0save_path = './{}Net.pth'.format(model_name)train_steps = len(train_loader)for epoch in range(epochs):    # train    net.train()    running_loss = 0.0    train_bar = tqdm(train_loader)    for step, data in enumerate(train_bar):        images, labels = data        optimizer.zero_grad()        outputs = net(images.to(device))        loss = loss_function(outputs, labels.to(device))        loss.backward()        optimizer.step()        # print statistics        running_loss += loss.item()        train_bar.desc = "train epoch[{}/{}] loss:{:.3f}".format(epoch + 1,                                                                 epochs,                                                                 loss)    # validate    net.eval()    acc = 0.0  # accumulate accurate number / epoch    with torch.no_grad():        val_bar =[WebMoney下载](https://www.gendan5.com/wallet/WebMoney.html) tqdm(validate_loader)        for val_data in val_bar:            val_images, val_labels = val_data            outputs = net(val_images.to(device))            predict_y = torch.max(outputs, dim=1)[1]            acc += torch.eq(predict_y, val_labels.to(device)).sum().item()    val_accurate = acc / val_num    print('[epoch %d] train_loss: %.3f  val_accuracy: %.3f' %          (epoch + 1, running_loss / train_steps, val_accurate))    if val_accurate > best_acc:        best_acc = val_accurate        torch.save(net.state_dict(), save_path)print('Finished Training')

if name == '__main__':

main()