Python 10 训练模型

青旅半醒 2021-10-30 08:08 346阅读 0赞

原文：https://www.cnblogs.com/denny402/p/7520063.html

原文：https://www.jianshu.com/p/84f72791806f

原文：https://blog.csdn.net/lee813/article/details/89609691

1、下载fashion-mnist数据集

地址：https://github.com/zalandoresearch/fashion-mnist

下面这四个都要下载，下载完成后，解压到同一个目录，我是解压到“E:/fashion\_mnist/”这个目录里面，好和下面的代码目录一致

![944853-20190719115814846-105963298.png][]

2、在Geany中执行下面这段代码。

这段代码里面，需要先用pip安装skimage、torch、torchvision，前两篇文章有安装步骤。

这段代码的作用：将下载下来的 二进制文件 转换为 图片，会在目录中生成两个文件夹和两个文本。

文件夹里面全是图片，图片的内容是数字，N多数字。

文本的内容主要是图片和真实数字的一个关联。

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

import os
    from skimage import io
    import torchvision.datasets.mnist as mnist
    
    root="E:/fashion_mnist/"
    train_set = (
        mnist.read_image_file(os.path.join(root, 'train-images-idx3-ubyte')),
        mnist.read_label_file(os.path.join(root, 'train-labels-idx1-ubyte'))
            )
    test_set = (
        mnist.read_image_file(os.path.join(root, 't10k-images-idx3-ubyte')),
        mnist.read_label_file(os.path.join(root, 't10k-labels-idx1-ubyte'))
            )
    print("training set :",train_set[0].size())
    print("test set :",test_set[0].size())
    
    def convert_to_img(train=True):
        if(train):
            f=open(root+'train.txt','w')
            data_path=root+'/train/'
            if(not os.path.exists(data_path)):
                os.makedirs(data_path)
            for i, (img,label) in enumerate(zip(train_set[0],train_set[1])):
                img_path=data_path+str(i)+'.jpg'
                io.imsave(img_path,img.numpy())
                f.write(img_path+' '+str(label)+'\n')
            f.close()
        else:
            f = open(root + 'test.txt', 'w')
            data_path = root + '/test/'
            if (not os.path.exists(data_path)):
                os.makedirs(data_path)
            for i, (img,label) in enumerate(zip(test_set[0],test_set[1])):
                img_path = data_path+ str(i) + '.jpg'
                io.imsave(img_path, img.numpy())
                f.write(img_path + ' ' + str(label) + '\n')
            f.close()
    
    convert_to_img(True)
    convert_to_img(False)

3、原文的这段代码编译会出错，主要是跟下载的数据有关，数据格式不一样，这里还在处理，原因是找到了的，就一个int的转换，下面贴出改过后的代码

出错的地方：

![944853-20190722093215233-2078894109.png][]

![944853-20190722093337184-1869376058.png][]

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

import torch
    import re
    import numpy
    from torch.autograd import Variable
    from torchvision import transforms
    from torch.utils.data import Dataset, DataLoader
    from PIL import Image
    root="E:/fashion_mnist/"
    
    
    def default_loader(path):
        return Image.open(path).convert('RGB')
    class MyDataset(Dataset):
        def __init__(self, txt, transform=None, target_transform=None, loader=default_loader):
            fh = open(txt, 'r')
            imgs = []
            for line in fh:
                line = line.strip('\n')
                line = line.rstrip()
                words = line.split()
                p1 = re.compile(r'[(](.*?)[)]', re.S)
                arr = re.findall(p1, words[1])
                word = arr[0]
                imgs.append((words[0],int(word)))
            self.imgs = imgs
            self.transform = transform
            self.target_transform = target_transform
            self.loader = loader
    
        def __getitem__(self, index):
            fn, label = self.imgs[index]
            img = self.loader(fn)
            if self.transform is not None:
                img = self.transform(img)
            return img,label
    
        def __len__(self):
            return len(self.imgs)
    
    train_data=MyDataset(txt=root+'train.txt', transform=transforms.ToTensor())
    test_data=MyDataset(txt=root+'test.txt', transform=transforms.ToTensor())
    train_loader = DataLoader(dataset=train_data, batch_size=64, shuffle=True)
    test_loader = DataLoader(dataset=test_data, batch_size=64)

3、原文的代码，还有一部分也会报错，ERROR如下。

唉，感叹一下，下次还是看一下语法那些，能读懂了代码再改吧，本想怎个拿来主义的，结果拿来了还是不能运行

![944853-20190722101859234-1102756917.png][]

解决-原文地址：https://blog.csdn.net/weixin\_43848267/article/details/88874584

解决：将 loss\_return.data\[0\] 改为 loss\_return.data

还有几个地方 也要将 .data\[0\] 改为 .data

4、可完整运行的代码

代码1：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

代码2：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

import re
    import numpy
    import torch
    from torch.autograd import Variable
    from torchvision import transforms
    from torch.utils.data import Dataset, DataLoader
    from PIL import Image
    root="E:/fashion_mnist/"
    
    # -----------------ready the dataset--------------------------
    def default_loader(path):
        return Image.open(path).convert('RGB')
    class MyDataset(Dataset):
        def __init__(self, txt, transform=None, target_transform=None, loader=default_loader):
            fh = open(txt, 'r')
            imgs = []
            for line in fh:
                line = line.strip('\n')
                line = line.rstrip()
                words = line.split()
                
                p1 = re.compile(r'[(](.*?)[)]', re.S) 
                arr = re.findall(p1, words[1])
                word = arr[0]
                
                imgs.append((words[0],int(word)))
            self.imgs = imgs
            self.transform = transform
            self.target_transform = target_transform
            self.loader = loader
    
        def __getitem__(self, index):
            fn, label = self.imgs[index]
            img = self.loader(fn)
            if self.transform is not None:
                img = self.transform(img)
            return img,label
    
        def __len__(self):
            return len(self.imgs)
    
    train_data=MyDataset(txt=root+'train.txt', transform=transforms.ToTensor())
    test_data=MyDataset(txt=root+'test.txt', transform=transforms.ToTensor())
    train_loader = DataLoader(dataset=train_data, batch_size=64, shuffle=True)
    test_loader = DataLoader(dataset=test_data, batch_size=64)
    
    
    #-----------------create the Net and training------------------------
    
    class Net(torch.nn.Module):
        def __init__(self):
            super(Net, self).__init__()
            self.conv1 = torch.nn.Sequential(
                torch.nn.Conv2d(3, 32, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2))
            self.conv2 = torch.nn.Sequential(
                torch.nn.Conv2d(32, 64, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2)
            )
            self.conv3 = torch.nn.Sequential(
                torch.nn.Conv2d(64, 64, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2)
            )
            self.dense = torch.nn.Sequential(
                torch.nn.Linear(64 * 3 * 3, 128),
                torch.nn.ReLU(),
                torch.nn.Linear(128, 10)
            )
    
        def forward(self, x):
            conv1_out = self.conv1(x)
            conv2_out = self.conv2(conv1_out)
            conv3_out = self.conv3(conv2_out)
            res = conv3_out.view(conv3_out.size(0), -1)
            out = self.dense(res)
            return out
    
    
    model = Net()
    print(model)
    
    optimizer = torch.optim.Adam(model.parameters())
    loss_func = torch.nn.CrossEntropyLoss()
    
    for epoch in range(10):
        print('epoch {}'.format(epoch + 1))
        # training-----------------------------
        train_loss = 0.
        train_acc = 0.
        for batch_x, batch_y in train_loader:
            batch_x, batch_y = Variable(batch_x), Variable(batch_y)
            out = model(batch_x)
            loss = loss_func(out, batch_y)
            train_loss += loss.item()
            pred = torch.max(out, 1)[1]
            train_correct = (pred == batch_y).sum()
            train_acc += train_correct.item()
            
            optimizer.zero_grad()
            loss.backward()
            optimizer.step()
        print('Train Loss: {:.6f}, Acc: {:.6f}'.format(train_loss / (len(
            train_data)), train_acc / (len(train_data))))
    
        # evaluation--------------------------------
        model.eval()
        eval_loss = 0.
        eval_acc = 0.
        for batch_x, batch_y in test_loader:
            batch_x, batch_y = Variable(batch_x), Variable(batch_y)
            out = model(batch_x)
            loss = loss_func(out, batch_y)
            eval_loss += loss.item()
            pred = torch.max(out, 1)[1]
            num_correct = (pred == batch_y).sum()
            eval_acc += num_correct.item()
        print('Test Loss: {:.6f}, Acc: {:.6f}'.format(eval_loss / (len(
            test_data)), eval_acc / (len(test_data))))

5、总结

提示：训练模型有点耗时，这里注意一下

图片如果过小，标签页里面单独打开图片会大些，排版搞得屁理解一下，一来没时间写文章，二来排版还没学，以后空了就会学。还是先把文章的质量提高了来

出现的问题主要是因为 torch的版本不同造成的，所以一会我把 我这里的环境贴出来，避免发生同样的错误。

6、环境

系统：win7 64位

Python 3.7.3

各个包的版本号，其它的好像就没啥了

![944853-20190722110513840-513746068.png][]

可测试代码-版本2

代码1：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

#coding=utf-8
    
    import os
    from skimage import io
    import torchvision.datasets.mnist as mnist
    
    root="E:/fashion_mnist/"
    train_set = (
        mnist.read_image_file(os.path.join(root, 'train-images-idx3-ubyte')),
        mnist.read_label_file(os.path.join(root, 'train-labels-idx1-ubyte'))
            )
    test_set = (
        mnist.read_image_file(os.path.join(root, 't10k-images-idx3-ubyte')),
        mnist.read_label_file(os.path.join(root, 't10k-labels-idx1-ubyte'))
            )
    print("training set :",train_set[0].size())
    print("test set :",test_set[0].size())
    
    def convert_to_img(train=True):
        if(train):
            f=open(root+'train.txt','w')
            data_path=root+'/train/'
            if(not os.path.exists(data_path)):
                os.makedirs(data_path)
            for i, (img,label) in enumerate(zip(train_set[0],train_set[1])):
                img_path=data_path+str(i)+'.jpg'            
                io.imsave(img_path,img.numpy())
                f.write(img_path+' '+str(label.numpy())+'\n') # label改为label.numpy()
            f.close()
        else:
            f = open(root + 'test.txt', 'w')
            data_path = root + '/test/'
            if (not os.path.exists(data_path)):
                os.makedirs(data_path)
            for i, (img,label) in enumerate(zip(test_set[0],test_set[1])):
                img_path = data_path+ str(i) + '.jpg'
                io.imsave(img_path, img.numpy())
                f.write(img_path + ' ' + str(label.numpy()) + '\n')
            f.close()
    
    convert_to_img(True)
    convert_to_img(False)

代码2：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

import torch
    from torch.autograd import Variable
    from torchvision import transforms
    from torch.utils.data import Dataset, DataLoader
    from PIL import Image
    root="E:/fashion_mnist/"
    
    
    def default_loader(path):
        return Image.open(path).convert('RGB')
    class MyDataset(Dataset):
        def __init__(self, txt, transform=None, target_transform=None, loader=default_loader):
            fh = open(txt, 'r')
            imgs = []
            for line in fh:
                line = line.strip('\n')
                line = line.rstrip()
                words = line.split()            
                imgs.append((words[0],int(words[1])))
            self.imgs = imgs
            self.transform = transform
            self.target_transform = target_transform
            self.loader = loader
    
        def __getitem__(self, index):
            fn, label = self.imgs[index]
            img = self.loader(fn)
            if self.transform is not None:
                img = self.transform(img)
            return img,label
    
        def __len__(self):
            return len(self.imgs)
    
    train_data=MyDataset(txt=root+'train.txt', transform=transforms.ToTensor())
    test_data=MyDataset(txt=root+'test.txt', transform=transforms.ToTensor())
    train_loader = DataLoader(dataset=train_data, batch_size=64, shuffle=True)
    test_loader = DataLoader(dataset=test_data, batch_size=64)
    
    
    
    
    
    #-----------------create the Net and training------------------------
    
    class Net(torch.nn.Module):
        def __init__(self):
            super(Net, self).__init__()
            self.conv1 = torch.nn.Sequential(
                torch.nn.Conv2d(3, 32, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2))
            self.conv2 = torch.nn.Sequential(
                torch.nn.Conv2d(32, 64, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2)
            )
            self.conv3 = torch.nn.Sequential(
                torch.nn.Conv2d(64, 64, 3, 1, 1),
                torch.nn.ReLU(),
                torch.nn.MaxPool2d(2)
            )
            self.dense = torch.nn.Sequential(
                torch.nn.Linear(64 * 3 * 3, 128),
                torch.nn.ReLU(),
                torch.nn.Linear(128, 10)
            )
    
        def forward(self, x):
            conv1_out = self.conv1(x)
            conv2_out = self.conv2(conv1_out)
            conv3_out = self.conv3(conv2_out)
            res = conv3_out.view(conv3_out.size(0), -1)
            out = self.dense(res)
            return out
    
    
    model = Net()
    print(model)
    
    optimizer = torch.optim.Adam(model.parameters())
    loss_func = torch.nn.CrossEntropyLoss()
    
    for epoch in range(10):
        print('epoch {}'.format(epoch + 1))
        # training-----------------------------
        train_loss = 0.
        train_acc = 0.
        for batch_x, batch_y in train_loader:
            batch_x, batch_y = Variable(batch_x), Variable(batch_y)
            out = model(batch_x)
            loss = loss_func(out, batch_y)        
            train_loss += loss.data
            pred = torch.max(out, 1)[1]
            train_correct = (pred == batch_y).sum()
            train_acc += train_correct.data
            optimizer.zero_grad()
            loss.backward()
            optimizer.step()
        print('Train Loss: {:.6f}, Acc: {:.6f}'.format(train_loss / (len(
            train_data)), train_acc / (len(train_data))))
    
        # evaluation--------------------------------
        model.eval()
        eval_loss = 0.
        eval_acc = 0.
        for batch_x, batch_y in test_loader:
            batch_x, batch_y = Variable(batch_x, volatile=True), Variable(batch_y, volatile=True)
            out = model(batch_x)
            loss = loss_func(out, batch_y)
            eval_loss += loss.data
            pred = torch.max(out, 1)[1]
            num_correct = (pred == batch_y).sum()
            eval_acc += num_correct.data
        print('Test Loss: {:.6f}, Acc: {:.6f}'.format(eval_loss / (len(
            test_data)), eval_acc / (len(test_data))))

版本2修改的地方

原文：https://blog.csdn.net/shang\_jia/article/details/82936074

原文：https://www.liangzl.com/get-article-detail-8524.html

注意：下面的代码不管，下面是第一次测试的时候，下载错了数据集

问题：这里的数据集是数字，不是这个数据集，代码里面是用的fashion-mnist这个数据集

1、下载mnist数据集

地址：http://yann.lecun.com/exdb/mnist/

下面这四个都要下载，下载完成后，解压到同一个目录，我是解压到“E:/fashion\_mnist/”这个目录里面，好和下面的代码目录一致

解压完成后，需要修改一下文件名，如（修改原因：保持和下面代码一样，避免出现其它问题）：

修改前：t10k-images.idx3-ubyte

修改后：t10k-images-idx3-ubyte

我是第一次弄这玩意，所以尽量弄得白痴些，走弯路很烦，有时候一点点小问题就弄半天，其实就是别人有那么一点没讲清楚，然后就会搞很久

![944853-20190719102139371-1758390468.png][]

![944853-20190719102513434-831404258.png][]

转载于:https://www.cnblogs.com/guxingy/p/11211714.html

[944853-20190719115814846-105963298.png]: /images/20211029/bf8d1b8d5f7446a484efd2316c4fd2c9.png
[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20211029/4e67a35bdf2149e5b4297dca3ba8822d.png
[944853-20190722093215233-2078894109.png]: /images/20211029/1b3530b1ed9442b9957f0b2df176907b.png
[944853-20190722093337184-1869376058.png]: /images/20211029/001c37d3e6804b4daff76e8d97973d76.png
[944853-20190722101859234-1102756917.png]: /images/20211029/d75fbd0c4d2f4b4a8d1f887815df5bad.png
[944853-20190722110513840-513746068.png]: /images/20211029/35a66c9173e54b7c98758a72b1abe26a.png
[944853-20190719102139371-1758390468.png]: /images/20211029/47a2401888df42b28394ad69702e043c.png
[944853-20190719102513434-831404258.png]: /images/20211029/21fed3439fc340f1a167f546649c2fce.png