Allow to run without installing into virtualenv

[schinckel]

trafficstars

I'd like to have pipdeptree installed once (using pipsi), and then be able to use it in a different virtualenv.

Is this a use case you'd consider supporting?

[nikolas]

I agree it's annoying to have to install pipdeptree inside the same virtualenv as the project you're looking up. I wrote a blog post about it here: http://www.columbia.edu/~njn2118/journal/2016/3/24.html

In addition, when I do install into the same virtualenv, the pipdeptree command fails:

$ ./ve/bin/pipdeptree 
Traceback (most recent call last):
  File "./ve/bin/pipdeptree", line 7, in <module>
    from pipdeptree import main
ImportError: No module named pipdeptree

I get around this by doing ./ve/bin/python -m pipdeptree, which works.

[Pike]

I'm pretty happy with activating my virtualenv, and just running

python /usr/local/lib/python2.7/site-packages/pipdeptree.py

As pipdeptree doesn't have any internal dependencies, that works like charm.

[iqbalansari]

I think this can be achieved by checking if pipdeptree is running a virtualenv and then re-execing with virtualenv's python binary. @naiquevin I can try implementing this, would you be interested in a PR for this?

[naiquevin]

Sure, always interested in PRs :-) Go ahead.

[E3V3A]

@iqbalansari any updates?

[iqbalansari]

Sorry just forgot about this, I had it working but there was some problem with bytecode versions or something (at which point I got busy with other things). Let me try and fix that issue

[merwok]

Another way of achieving this would be an option to read the package list from a file rather than the environment (similar to how safety check accepts a requirements file as input)

[gaborbernat]

The --python flag has been added.