FICO® Xpress Mosel Python Interface

Run FICO Xpress Mosel optimization models directly from Python. Define your model in Mosel, solve it with the full power of the Xpress solver, and exchange data and results with Python objects:

from io import BytesIO, StringIO
import moselpy as mp

MODEL = """
model "production"
  uses "mmxprs"
  declarations
    PRODUCTS = {"Chairs", "Tables", "Desks"}
    Profit:      array(PRODUCTS) of real
    Capacity:    real
    produce:     array(PRODUCTS) of mpvar
    TotalProfit: real
  end-declarations
  initializations from "moselpy:" Profit Capacity end-initializations
  forall(p in PRODUCTS) produce(p) is_integer
  sum(p in PRODUCTS) produce(p) <= Capacity
  maximize(sum(p in PRODUCTS) Profit(p) * produce(p))
  TotalProfit := getobjval
  initializations to "moselpy:" TotalProfit end-initializations
end-model
"""

mp.symbols["src"] = StringIO(MODEL)
mp.symbols["bim"] = BytesIO()
mp.compile_model("moselpy:src", "moselpy:bim")
del mp.symbols["src"]

mp.symbols["bim"].seek(0)
model = mp.load_model("moselpy:bim")
del mp.symbols["bim"]

results = model.run(input_data={
    "Profit":   {"Chairs": 45, "Tables": 80, "Desks": 120},
    "Capacity": 10,
})
print("Total profit:", results["TotalProfit"])

With the moselpy module, one can control Mosel optimization models using the Python® programming language. The module allows for:

• Compiling, loading, and running Mosel models (.mos source or .bim binary)
• Passing input data from Python to Mosel and retrieving results, supporting scalars, arrays, sets, dicts, NumPy arrays, and Pandas DataFrames
• Redirecting Mosel output streams to Python file-like objects
• Introspecting model symbols and querying solution status

Installation

Install from PyPI:

pip install moselpy

A valid FICO Xpress installation with Mosel support is required at runtime. Set the XPRESSDIR environment variable to point to the Xpress installation directory before importing the module.

Licensing

The Xpress software is governed by the Xpress Shrinkwrap License Agreement. When downloading the package, you accept the license terms. A copy of the Xpress Shrinkwrap License is stored in the file LICENSE.txt in the dist-info directory of the moselpy module.

Miscellaneous

"Python" is a registered trademark of the Python Software Foundation. "FICO" is a registered trademark of Fair Isaac Corporation in the United States and may be a registered trademark of Fair Isaac Corporation in other countries. Other product and company names herein may be trademarks of their respective owners.