msolveio

Strict Python I/O for msolve: canonical input, mode-required output. Gröbner-mode (-g) only in v0.1. Solver-mode bytes are rejected, not interpreted.

msolveio writes .ms files that msolve 0.10.x will parse the way you meant, and reads back only the one output language it can identify with certainty. It is not a CAS and not a Gröbner engine.

Install

pip install msolveio

You also need a system msolve 0.10.x binary on PATH (or pass binary=). msolveio has no runtime dependencies.

Usage

from msolveio import emit_system, parse_groebner, run_groebner, MsolveAmbiguous

source = emit_system(
    ["x^2+y", "x*y-1"],
    variables=["x", "y"],
    characteristic=0,
)

result = run_groebner(source, gb=2, timeout=60)

print(result.output.unit_ideal)  # False
print(result.output.basis)       # ('y^2+x', 'x*y-1', 'x^2+y')
print(result.msolve_version)     # '0.10.1'

emit_system raises MsolveInputError rather than rewriting input: parentheses, post-monomial division (x/2), repeated monomials, unknown identifiers, and coefficients that would overflow msolve's 64-bit read are all refused. Leading rationals (1/2*x) are allowed over Q only.

parse_groebner requires msolve's # comment header. That header is the only thing in the bytes that says which mode produced them, so it is load-bearing. Feeding it solver output raises MsolveAmbiguous instead of returning a basis:

parse_groebner("[-1]:")  # MsolveAmbiguous

This matters because the two languages invert each other. In solver mode [-1]: means no solutions; in Gröbner mode the unit ideal — the same fact — prints as [1]:. A parser that guesses gets the answer exactly backwards.

Not supported in v0.1

• Solver mode, real-root isolation, and -P parametrization output — these raise, and are never interpreted as a basis.
• JSON output, Macaulay2 format, or any other msolve serialization.
• sympy / flint / numpy interop. Basis elements are returned as strings, exactly as msolve printed them. Nothing is eval'd.

A note on characteristic

msolve 0.10.1 labels some unlifted rational Gröbner bases as characteristic 0 regardless of whether a lift to Q actually happened. GroebnerOutput.characteristic reports what msolve printed and nothing more; msolveio does not pretend to know better.

License

MIT © 2026 DC Posch — https://github.com/dcposch/msolveio