ImportError: FloatProgress not found. Please update jupyter and ipywidgets.问题
一、问题描述：
在进行深度学习导包时，运行代码：
import torch
import torchvision
import torchvision.transforms as transforms
import matplotlib.pyplot as plt
import sys
sys.path.append("..")
import d2lzh_pytorch as d2l
出现了“ImportError: FloatProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html” 错误。错误代码如下：
Downloading http://fashion-mnist.s3-website.eu-central-1.amazonaws.com/train-images-idx3-ubyte.gz to C:\Users\木子/Datasets/FashionMNIST\FashionMNIST\raw\train-images-idx3-ubyte.gz
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\tqdm\notebook.py in status_printer(_, total, desc, ncols)
97 else: # No total? Show info style bar with no progress tqdm status
---> 98 pbar = IProgress(min=0, max=1)
99 pbar.value = 1
NameError: name 'IProgress' is not defined
During handling of the above exception, another exception occurred:
ImportError Traceback (most recent call last)
<ipython-input-1-e1dda4d0e124> in <module>
5 import sys
6 sys.path.append("..")
----> 7 import d2lzh_pytorch as d2l
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\d2lzh_pytorch\__init__.py in <module>
----> 1 from .utils import *
2
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\d2lzh_pytorch\utils.py in <module>
6 import d2lzh_pytorch as d2l
7
----> 8 minst_train = torchvision.datasets.FashionMNIST(root = '~/Datasets/FashionMNIST',train=True,download=True,transform=transforms.ToTensor())
9 minst_test = torchvision.datasets.FashionMNIST(root = '~/Datasets/FashionMNIST',train=False,download=True,transform=transforms.ToTensor())
10 print(type(mnist_train))
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\torchvision\datasets\mnist.py in __init__(self, root, train, transform, target_transform, download)
68
69 if download:
---> 70 self.download()
71
72 if not self._check_exists():
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\torchvision\datasets\mnist.py in download(self)
135 for url, md5 in self.resources:
136 filename = url.rpartition('/')[2]
--> 137 download_and_extract_archive(url, download_root=self.raw_folder, filename=filename, md5=md5)
138
139 # process and save as torch files
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\torchvision\datasets\utils.py in download_and_extract_archive(url, download_root, extract_root, filename, md5, remove_finished)
262 filename = os.path.basename(url)
263
--> 264 download_url(url, download_root, filename, md5)
265
266 archive = os.path.join(download_root, filename)
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\torchvision\datasets\utils.py in download_url(url, root, filename, md5)
83 urllib.request.urlretrieve(
84 url, fpath,
---> 85 reporthook=gen_bar_updater()
86 )
87 except (urllib.error.URLError, IOError) as e:
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\torchvision\datasets\utils.py in gen_bar_updater()
13
14 def gen_bar_updater():
---> 15 pbar = tqdm(total=None)
16
17 def bar_update(count, block_size, total_size):
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\tqdm\notebook.py in __init__(self, *args, **kwargs)
207 total = self.total * unit_scale if self.total else self.total
208 self.container = self.status_printer(
--> 209 self.fp, total, self.desc, self.ncols)
210 self.sp = self.display
211
D:\InstallSoftware\Anaconda\envs\spyder_py3.5\lib\site-packages\tqdm\notebook.py in status_printer(_, total, desc, ncols)
102 # #187 #451 #558
103 raise ImportError(
--> 104 "FloatProgress not found. Please update jupyter and ipywidgets."
105 " See https://ipywidgets.readthedocs.io/en/stable"
106 "/user_install.html")
ImportError: FloatProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html
二、问题分析：
阅读上面即可知，大多是因为ipywidgets原因：版本或者根本没有安装ipywidgets插件。
三、问题解决：
1. pip安装命令
建议使用pip命令安装，使用conda安装我出现了一系列奇奇怪怪的问题，同时个人建议安装5.0.0版本
pip install ipywidgets==5.0.0，避免在jupyter notebook中出现找不到ipywidgets插件的问题。
pip install ipywidgets
jupyter nbextension enable --py widgetsnbextension
2. conda 安装命令
在多个环境中安装
有时Jupyter Notebook和IPython内核安装在不同的环境（virtualenv或conda环境）中。当使用环境提供不同的IPython内核时会发生这种情况。在这种情况下，安装需要两个步骤。
首先，您需要widgetsnbextension在包含Jupyter Notebook服务器的环境中安装软件包。接下来，您需要ipywidgets在将使用ipywidgets的每个内核环境中进行安装 。
如果使用conda环境，并且笔记本计算机安装在 base环境中，内核安装在环境中py36，则命令为：
conda install -n base -c conda-forge widgetsnbextension
conda install -n py36 -c conda-forge ipywidgets
如果你使用conda 安装出现了“关于ipywidgets插件，错误'Widget Javascript not detected. It may not be installed or enabled properly.'”这个问题参考博客：关于ipywidgets插件，错误'Widget Javascript not detected. It may not be installed or enabled properly.
