Wrapper modules

The ArcPy module is a "wrapper" module. It "wraps" a Python code interface over the existing ArcGIS tools and source code, allowing us to access these tools within our scripts. Wrapper modules are common in Python, and are so named because they "wrap" Python onto the tools we will need. They allow us to use Python to interface with programs written in C or other programming languages using the API of those programs. The wrapper module os allows for operating system operations.

For example, wrapper modules make it possible to extract data from an Excel spreadsheet, transform the data into another format such as a shapefile, and load it into an MXD as a layer. Not all modules are wrappers; some modules are written in "pure Python", and perform their analysis and computations using Python syntax. Either way, the end result is that a computer and its programs are available to be manipulated and controlled using Python.