Often times, your Python scripts require 3rd party Python libraries. For example, the sample tools located here: http://www.arcgis.com/home/item.html?id=f3d91b8f852042e289e09a7ec8342431 requires xlrd, xlwt, and openpyxl Python libraries. This sample includes all of the dependent libraries, and demonstrates just how easy it is.
The secret to most Python modules and packages: they’re just files. You can copy any Python library into the same folder as the .py file that imports them and it will just work (Note: in the case of C extensions and compiled bytecode, the Python version and architecture must match). Here is the layout of the folder with the libraries we mentioned before:
Finding the install location of a library
Usually the Python library is located in the site-packages folder within the Python install directory, however, if it is not located in the site-packages folder and you are uncertain where it is installed, here is a Python sample to locate Python modules installed on your computer.....