Why is python's pip install behaving strangely in a script but fine in python prompt? - pip

Question

I'm trying to install a module from withing a python script using pip. Here is the contents of script.py:
#/usr/bin/python2.7
# I'm the file called `script.py`
import sys, importlib, pip
print(sys.version); print(sys.path) # For debugging
try:
importlib.import_module('docopt')
except ImportError:
pip.main(['install', '-U', 'docopt'])
finally:
globals()[pack] = importlib.import_module('docopt')
Runnting this script, e.g. using python2.7 script.py gives me:
$ python2.7 script.py
2.7.9 (default, Oct 3 2016, 17:42:24)
[GCC 4.3.2 20081105 (Red Hat 4.3.2-7)]
['/usr/lib/python27.zip', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/lib/python2.7/site-packages']
No module named docopt
Downloading/unpacking docopt
Cannot fetch index base URL https://pypi.python.org/simple/
Could not find any downloads that satisfy the requirement docopt
Cleaning up...
No distributions at all found for docopt
Storing debug log for failure in /root/.pip/pip.log
Traceback (most recent call last):
[...]
File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
ImportError: No module named docopt
So problems with internet connection/ssl or something transport related. However, the same commands work perfectly fine in the python interactive interpreter, when I enter them by hand (copy&paste them):
$ python2.7
Python 2.7.9 (default, Oct 3 2016, 17:42:24)
[GCC 4.3.2 20081105 (Red Hat 4.3.2-7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pip, sys
>>> print(sys.path)
['/usr/lib/python27.zip', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/lib/python2.7/site-packages']
>>> pip.main(['install', '-U', 'docopt'])
Downloading/unpacking docopt
Downloading docopt-0.6.2.tar.gz
Running setup.py (path:/tmp/pip_build_root/docopt/setup.py) egg_info for package docopt
Installing collected packages: docopt
Running setup.py install for docopt
Successfully installed docopt
Cleaning up...
0
Again, the thing that weirds me out is, that it works interactively i.e. running python2.7 in the shell and then entering the very same code by hand. However, not when I run the script file with python2.7 script.py. So In one case, on the same machine, the same interpreter has internet access in the other case it does not.
I'm running out of troubleshooting ideas. I used the same machine and user to get above results. There is no python-startup file, so that is not making the commands magically work interactively. The contents of sys.path are the same in both cases. I'm not behind a proxy. Any ideas what could be missing in the script?

Answer 1

Cannot fetch index base URL https://pypi.python.org/simple/
indicates that for some reason your python interpreter cannot access to internet. There can be plenty of reasons for that. Do you use a HTTP proxy ?