我正在Ubuntu 12.04中使用以下requirements.txt文件安装几个Python包:
numpy>=1.8.2,<2.0.0
matplotlib>=1.3.1,<2.0.0
scipy>=0.14.0,<1.0.0
astroML>=0.2,<1.0
scikit-learn>=0.14.1,<1.0.0
rpy2>=2.4.3,<3.0.0
下面是两条命令:
$ pip install --download=/tmp -r requirements.txt
$ pip install --user --no-index --find-links=/tmp -r requirements.txt
(第一个程序下载包，第二个程序安装包)。
进程经常被错误停止:
Could not find a version that satisfies the requirement <package> (from matplotlib<2.0.0,>=1.3.1->-r requirements.txt (line 2)) (from versions: )
No matching distribution found for <package> (from matplotlib<2.0.0,>=1.3.1->-r requirements.txt (line 2))
我手动修复:
pip install --user <package>
然后再次运行第二个PIP安装命令。
但这只适用于特定的包装。当我再次运行第二个pip install命令时，进程停止了，现在抱怨有另一个所需的包，我需要再次重复该过程，即:手动安装新的所需包(使用上面的命令)，然后运行第二个pip install命令。
到目前为止，我不得不手动安装6,pytz, nose，现在它抱怨需要mock。
有没有办法告诉pip自动安装所有需要的依赖项，这样我就不必手动一个一个地安装了?
补充:这只发生在Ubuntu 12.04 BTW中。在Ubuntu 14.04中，应用在requirements.txt文件上的pip安装命令可以正常工作。
只是提醒谁谷歌这个错误，来这里。
假设我得到这个错误:
$ python3 example.py
Traceback (most recent call last):
File "example.py", line 7, in <module>
import aalib
ModuleNotFoundError: No module named 'aalib'
既然它提到了aalib，我想试试aalib:
$ python3.8 -m pip install aalib
ERROR: Could not find a version that satisfies the requirement aalib (from versions: none)
ERROR: No matching distribution found for aalib
但它实际上是错误的包名，确保pip搜索(在撰写时服务已禁用)，或谷歌，或在pypi网站上搜索以获得准确的包名:
安装成功:
$ python3.8 -m pip install python-aalib
Collecting python-aalib
Downloading python-aalib-0.3.2.tar.gz (14 kB)
...
正如pip——help所说:
$ python3.8 -m pip --help
...
-v, --verbose Give more output. Option is additive, and can be used up to 3 times.
为了有一个系统的方法来找出根本原因，而不是依靠运气，你可以在pip命令中附加-vvv选项来查看详细信息，例如:
$ python3.8 -u -m pip install aalib -vvv
User install by explicit request
Created temporary directory: /tmp/pip-ephem-wheel-cache-b3ghm9eb
Created temporary directory: /tmp/pip-req-tracker-ygwnj94r
Initialized build tracking at /tmp/pip-req-tracker-ygwnj94r
Created build tracker: /tmp/pip-req-tracker-ygwnj94r
Entered build tracker: /tmp/pip-req-tracker-ygwnj94r
Created temporary directory: /tmp/pip-install-jfurrdbb
1 location(s) to search for versions of aalib:
* https://pypi.org/simple/aalib/
Fetching project page and analyzing links: https://pypi.org/simple/aalib/
Getting page https://pypi.org/simple/aalib/
Found index url https://pypi.org/simple
Getting credentials from keyring for https://pypi.org/simple
Getting credentials from keyring for pypi.org
Looking up "https://pypi.org/simple/aalib/" in the cache
Request header has "max_age" as 0, cache bypassed
Starting new HTTPS connection (1): pypi.org:443
https://pypi.org:443 "GET /simple/aalib/ HTTP/1.1" 404 13
[hole] Status code 404 not in (200, 203, 300, 301)
Could not fetch URL https://pypi.org/simple/aalib/: 404 Client Error: Not Found for url: https://pypi.org/simple/aalib/ - skipping
Given no hashes to check 0 links for project 'aalib': discarding no candidates
ERROR: Could not find a version that satisfies the requirement aalib (from versions: none)
Cleaning up...
Removed build tracker: '/tmp/pip-req-tracker-ygwnj94r'
ERROR: No matching distribution found for aalib
Exception information:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/pip/_internal/cli/base_command.py", line 186, in _main
status = self.run(options, args)
File "/usr/lib/python3/dist-packages/pip/_internal/commands/install.py", line 357, in run
resolver.resolve(requirement_set)
File "/usr/lib/python3/dist-packages/pip/_internal/legacy_resolve.py", line 177, in resolve
discovered_reqs.extend(self._resolve_one(requirement_set, req))
File "/usr/lib/python3/dist-packages/pip/_internal/legacy_resolve.py", line 333, in _resolve_one
abstract_dist = self._get_abstract_dist_for(req_to_install)
File "/usr/lib/python3/dist-packages/pip/_internal/legacy_resolve.py", line 281, in _get_abstract_dist_for
req.populate_link(self.finder, upgrade_allowed, require_hashes)
File "/usr/lib/python3/dist-packages/pip/_internal/req/req_install.py", line 249, in populate_link
self.link = finder.find_requirement(self, upgrade)
File "/usr/lib/python3/dist-packages/pip/_internal/index/package_finder.py", line 926, in find_requirement
raise DistributionNotFound(
pip._internal.exceptions.DistributionNotFound: No matching distribution found for aalib
从上面的日志中，很明显没有找到URL https://pypi.org/simple/aalib/ 404。然后您可以猜测导致404的可能原因，即错误的包名。另外，我可以修改pip模块的相关python文件，用上面的日志进一步调试。要编辑.whl文件，可以使用wheel命令解压和打包。
因为这是一个相当烦人的问题，可能会让初学者陷入很长一段时间，在这里我写了一个完整的公会。
如果您正在运行pip安装包或python -m pip安装包，并且报告了不匹配的版本发现错误，下面是如何解决问题。
在浏览器上搜索你的包，例如我的包是pycypto，在这里我搜索pycypto pypi
找到你的包，打开pypi上的链接，点击下载文件
打开一个python shell，导入任何你安装的包，例如，我之前安装过Pillow。
>>> import PIL
>>> PIL.__path__
['/Applications/MAMP/htdocs/canvas/src/zzd/env/lib/python3.7/site-packages/PIL']
包中。__path__函数将给你所有包应该进入的路径。
加:
如果您不知道之前安装了什么包，运行PIP list以获得已安装包的列表。
获取路径后，打开shell, CD到该路径
cd /Applications/MAMP/htdocs/canvas/src/zzd/env/lib/python3.7/site-packages/
open
解压下载的文件，将其拖到site-packages中。
CD到下载目录下，运行setup.py进行安装
cd pycrypto-2.6.1
python setup.py install
然后，您应该能够在python中导入和使用该包。
