Python cassandra-driver: The C extension needed to use libev was not found
Question: I have Cassandra python driver version 2.5.1 installed with all required
dependencies that is libev4, libev-dev, gcc, python-dev. However I am getting
following error while importing `LibevConnection`

> "The C extension needed to use libev was not found. This probably means that
> you didn't have the required build dependencies when installing the driver"

I tried reinstalling and even installed latest version of the driver with no
success. I am using Ubuntu 12.04.


Answer: When I checked I had all the dependencies installed but probably not when I
installed the driver. Before I tried reinstalling I tried installing newest
version which made conflict with existing installation.

**So the problem was:** Not having dependency installed before installing
python driver and then multiple installation of the driver.

**Solution** Remove all the version of Cassandra python driver completely from
the system (Delete the relevant eggs). Make sure you have all the
[dependencies installed](http://datastax.github.io/python-
driver/installation.html#c-extensions). After that simply install the required
version.

