Tidy up virtual_environment.rst

Some small fixes.

Author: StevenMaude

virtual_environment.rst

@@ -1,48 +1,50 @@
 Virtual Environment
 -------------------
 
-Have you ever heard of ``virtualenv``? The chances are that if you are a
-beginner then you might not have heard about it but if you are a
-seasoned programmer than it's a vital part of your toolset. So what
-``virtualenv`` really is? ``Virtualenv`` is a tool which allows us to
+Have you ever heard of ``virtualenv``? If you are a beginner,
+then you might not have heard about it but if you are a
+seasoned programmer then it may well be a vital part of your toolset. 
+
+So what is ``virtualenv``? ``Virtualenv`` is a tool which allows us to
 make isolated python environments. Imagine you have an application that
-needs version 2 of a LibraryBar, but another application requires
+needs version 2 of a library, but another application requires
 version 3. How can you use and develop both these applications?
 
 If you install everything into ``/usr/lib/python2.7/site-packages`` (or
 whatever your platform's standard location is), it's easy to end up in a
-situation where you unintentionally upgrade a package that shouldn't be
-upgraded. In another case just imagine that you have an application
-which is fully developed and you do not want to make any change to the
-libraries it is using but at the same time you start developing another
-application which requires the updated versions of those libraries. What
-will you do? It is where ``virtualenv`` comes into play. It creates
-isolated environments for your python application and allows you to
-install Python libraries in that isolated environment instead of
-installing them globally.
-
-In order to install it just type this command in the shell:
+situation where you unintentionally upgrade a package.
+
+In another case, imagine that you have an application which is fully
+developed and you do not want to make any change to the libraries it is
+using but at the same time you start developing another application
+which requires the updated versions of those libraries.
+
+What will you do? Use ``virtualenv``! It creates isolated environments
+for your python application and allows you to install Python libraries
+in that isolated environment instead of installing them globally.
+
+To install it, just type this command in the shell:
 
 .. code:: python
 
     $ pip install virtualenv
 
-Now i am going to list some of it's commands. The most important ones
-are:
+The most important commands are:
 
 -  ``$ virtualenv myproject``
 -  ``$ source bin/activate``
 
 This first one makes an isolated virtualenv environment in the
 ``myproject`` folder and the second command activates that isolated
-environment. While running the first command you have to make a
-decision.
+environment.
+
+While creating the virtualenv you have to make a decision. Do you
+want this virtualenv to use packages from your system ``site-packages``
+or install them in the virtualenv’s site-packages? By default,
+virtualenv will not give access to the global ``site-packages``.
 
-Do you want this virtualenv to use packages from your system
-``site-packages`` or install them in the virtualenv’s site-packages? By
-default, virtualenv will not give access to the global ``site-packages``.
 If you want your ``virtualenv`` to have access to your systems
-``site-packages`` use the ``--system-site-packages`` switch when creating
+``site-packages``, use the ``--system-site-packages`` switch when creating
 your virtualenv like this:
 
 .. code:: python
@@ -55,6 +57,9 @@ You can turn off the ``env`` by typing:
 
     $ deactivate
 
+Running `python` after deactivating will use your system installation
+of Python again.
+
 **Bonus**
 
 You can use ``smartcd`` which is a library for bash and zsh and allows
@@ -63,7 +68,6 @@ helpful to activate and deactivate a ``virtualenv`` when you change
 directories. I have used it quite a lot and love it. You can read more
 about it on `GitHub <https://github.com/cxreg/smartcd>`__
 
-This was just a short intro to virtualenv. There's a lot more to it. For
-further study i recommend `this
-link. <http://docs.python-guide.org/en/latest/dev/virtualenvs/>`__
-It will remove all of your confusions about virtualenv.
+This was just a short intro to virtualenv. There's a lot more to it; `this
+link <http://docs.python-guide.org/en/latest/dev/virtualenvs/>`__ has more
+information.