python - Could not find a version that satisfies the requirement <package>

Question

I'm installing several Python packages in Ubuntu 12.04 using the following requirements.txt file:

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

and these two commands:

$ pip install --download=/tmp -r requirements.txt
$ pip install --user --no-index --find-links=/tmp -r requirements.txt

(the first one downloads the packages and the second one installs them).

The process is frequently stopped with the error:

  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))

which I fix manually with:

pip install --user <package>

and then run the second pip install command again.

But that only works for that particular package. When I run the second pip install command again, the process is stopped now complaining about another required package and I need to repeat the process again, ie: install the new required package manually (with the command above) and then run the second pip install command.

So far I've had to manually install six, pytz, nose, and now it's complaining about needing mock.

Is there a way to tell pip to automatically install all needed dependencies so I don't have to do it manually one by one?

Add: This only happens in Ubuntu 12.04 BTW. In Ubuntu 14.04 the pip install commands applied on the requirements.txt file work without issues.

Answer 1

I had installed python3 but my python in /usr/bin/python was still the old 2.7 version

This worked (<pkg> was pyserial in my case):

python3 -m pip install <pkg>