pip 安装 web3 @ ubuntu 错误 - 无法安装 web3

Question

尝试从 pip 安装 web3 时遇到以下问题：

$ sudo pip install web3
The directory '/home/chris/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/home/chris/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting web3
  Downloading https://files.pythonhosted.org/packages/96/76/6313b5d55edb5ac6fdbde9beacafefb04fccd692348ed2085856c95dda25/web3-4.1.0.tar.gz (85kB)
    100% |████████████████████████████████| 92kB 1.4MB/s 
Collecting cytoolz<1.0.0,>=0.9.0 (from web3)
  Downloading https://files.pythonhosted.org/packages/36/f4/9728ba01ccb2f55df9a5af029b48ba0aaca1081bbd7823ea2ee223ba7a42/cytoolz-0.9.0.1.tar.gz (443kB)
    100% |████████████████████████████████| 450kB 3.6MB/s 
Collecting eth-abi<2,>=1.0.0 (from web3)
  Downloading https://files.pythonhosted.org/packages/8d/f1/212b138e8e2e46788054b456a068ae060f07464fd03f5f7ec0eb749c35d0/eth-abi-1.0.0.tar.gz
Collecting eth-account==0.1.0-alpha.2 (from web3)
  Downloading https://files.pythonhosted.org/packages/57/8e/12a906f171f2860c0baf0f07bde4d7b390a3eacb29adc8341c7bbec356f6/eth-account-0.1.0a2.tar.gz
Collecting eth-utils<2.0.0,>=1.0.1 (from web3)
  Downloading https://files.pythonhosted.org/packages/6f/08/0787c6ccb1b8dca4a15c12f67ed3d383f9f361eeb1836d6fe698caf46bca/eth-utils-1.0.3.tar.gz
Collecting hexbytes<1.0.0,>=0.1.0 (from web3)
  Downloading https://files.pythonhosted.org/packages/81/15/fcd3a5ad583673ce52f0aac8e1246b91e7c88acbeae47863c30bfb264436/hexbytes-0.1.0.tar.gz
    Complete output from command python setup.py egg_info:
    zip_safe flag not set; analyzing archive contents...
    pypandoc.__init__: module references __file__
    Installed /tmp/pip-install-KPGcEs/hexbytes/.eggs/pypandoc-1.4-py2.7.egg
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-KPGcEs/hexbytes/setup.py", line 67, in <module>
        'Programming Language :: Python :: Implementation :: PyPy',
      File "/usr/local/lib/python2.7/dist-packages/setuptools/__init__.py", line 129, in setup
        return distutils.core.setup(**attrs)
      File "/usr/lib/python2.7/distutils/core.py", line 111, in setup
        _setup_distribution = dist = klass(attrs)
      File "/usr/local/lib/python2.7/dist-packages/setuptools/dist.py", line 372, in __init__
        _Distribution.__init__(self, attrs)
      File "/usr/lib/python2.7/distutils/dist.py", line 287, in __init__
        self.finalize_options()
      File "/usr/local/lib/python2.7/dist-packages/setuptools/dist.py", line 528, in finalize_options
        ep.load()(self, ep.name, value)
      File "/tmp/pip-install-KPGcEs/hexbytes/.eggs/setuptools_markdown-0.2-py2.7.egg/setuptools_markdown.py", line 22, in long_description_markdown_filename
        output = pypandoc.convert(markdown_filename, 'rst')
      File "/tmp/pip-install-KPGcEs/hexbytes/.eggs/pypandoc-1.4-py2.7.egg/pypandoc/__init__.py", line 66, in convert
        raise RuntimeError("Format missing, but need one (identified source as text as no "
    RuntimeError: Format missing, but need one (identified source as text as no file with that name was found).
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-KPGcEs/hexbytes/

因此，每当我尝试.py脚本时，都会收到以下错误：

from web3 import Web3, KeepAliveRPCProvider, IPCProvider
ImportError: cannot import name Web3

知道是什么原因造成的，或者如何解决吗？

Answer 1

我能够通过将web3==4.1.0移动到requirements.txt文件中并运行pip install -r requirements.txt来解决这个问题。

不知道为什么它有效。不过，尝试从setup.py文件安装它时仍然失败。

顺便说一下，根据web3自述文件，他们只支持python 3.5+。