The book contains a complete guide to Python Optimization Modeling Objects, an open source package for formulating and solving large-scale optimization problems. Pyomo includes Python classes for defining sparse sets, parameters, and variables that write algebraic expressions that define objective functions and constraints. In addition, the program can be used both from the command line and from the interactive Python environment, which greatly simplifies the creation of Pyomo models, the use of various optimizers and the study of solutions. With numerous examples illustrating different ways of formulating models, the book perfectly reveals the breadth of modeling tools supported by Pyomo and its approaches to complex practical applications.