Setting up the Python API of CPLEX
The Python API of CPLEX is part of IBM ILOG CPLEX Optimization Studio.
The CPLEX Python API is a lightweight wrapper around the C API (CPLEX Callable Library). As such, it provides access to nearly all of the functionality CPLEX has to offer. Variables and constraints are identified by their indices in the matrix. This topic explains how to set up the CPLEX Python API.
DOcplex is an object-oriented modeling Python API that is numpy/pandas friendly. The model can be solved locally (using the CPLEX Python API under the hood), or on the cloud. In addition to providing access to CPLEX for mathematical programming, it can also be used to access the CP Optimizer constraint programming engine. For more information about using the DOcplex Python API with the CPLEX or the CP Optimizer engines, see DOcplex Python Modeling API.
The modules associated with the CPLEX Python API reside in the directory yourCPLEXhome/python/VERSION/PLATFORM, (or in the folder yourCPLEXhome\python\VERSION\PLATFORM) where yourCPLEXhome specifies the location where CPLEX is installed as part of IBM ILOG CPLEX Optimization Studio, VERSION designates a version of Python compatible with CPLEX, and PLATFORM stands for your combination of operating system and compiler.
- The preferred and most common way is to use the script setup.py located in the directory yourCPLEXhome/python/VERSION/PLATFORM (or in the folder yourCPLEXhome\python\VERSION\PLATFORM).
- Alternatively, you can
set the environment variable
PYTHONPATH
to yourCPLEXhome/python/VERSION/PLATFORM and start running Python scripts with CPLEX.
Using the script setup.py
To install the CPLEX-Python modules on your system, use
the script setup.py located in
yourCplexhome/python/VERSION/PLATFORM.
If you want to install the CPLEX-Python modules in a nondefault location,
use the option --home
to identify the installation
directory. For example, to install the CPLEX-Python modules in the
default location, use the following command from the command line:
python setup.py install
To install in the directory yourPythonPackageshome/cplex, use the following command from the command line:
python setup.py install --home yourPythonPackageshome/cplex
Both of those commands (default and home-specified) invoke
the Python package distutils
.
For other options available with that package, consult the documentation
of Python distutils
.
Setting the environment variable PYTHONPATH
If you
run multiple versions of CPLEX side-by-side, then use
this way of declaring the location of CPLEX and its Python API to
your Python installation by means of the environment variable
PYTHONPATH
.
To start using the CPLEX Python API,
set the Python path environment variable
PYTHONPATH
to the value of yourCplexhome/python/VERSION/PLATFORM.
Setting this environment variable enables that version of Python to find the
CPLEX modules that it needs to run Python commands and scripts
that use the CPLEX Python API.
Next steps
After setting up your Python environment by means of one of those alternative methods, you can proceed to the topic Starting the CPLEX Python API.