Noissue - Update virtualenv instructions

README.rst

 python-abp
 ==========
 
 This repository contains a library for working with Adblock Plus filter lists,
 a script for rendering diffs between filter lists, and the script that is used
 for building Adblock Plus filter lists from the form in which they are authored
 into the format suitable for consumption by the adblocking software (aka
 rendering).
 
 .. contents::
@@ skipping 193 matching lines @@
 
 All public functions, classes and methods should have docstrings compliant with
 `NumPy/SciPy documentation guide <https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt>`_.
 One exception is the constructors of classes that the user is not expected to
 instantiate (such as exceptions).
 
 
 Using the library with R
 ------------------------
 
-Clone the repo to your local machine. Then create a virtualenv and install
-python-abp there::
+``python-abp`` can be installed directly onto your system, or in a virtual
+environment. To install it directly onto your system::
 
-    $ cd python-abp
-    $ virtualenv env
-    $ pip install --upgrade .
+    $ pip install --upgrade python-abp
+
+To install it in a virtual environment::
+
+    $ virtualenv venv
+    $ venv/bin/pip install --upgrade python-abp
 
 
 Then import it with ``reticulate`` in R:
 
 .. code-block:: R
 
     > library(reticulate)
-    > use_virtualenv("~/python-abp/env", required=TRUE)
+    > use_virtualenv("~/python-abp/env", required=TRUE)  # If using virtualenv
     > abp <- import("abp.filters.rpy")
 
 Now you can use the functions with ``abp$functionname``, e.g.
 ``abp.line2dict("@@||g.doubleclick.net/pagead/$subdocument,domain=hon30.org")``.