phivenv/Lib/site-packages/sympy/parsing/tests/test_latex_deps.py

from sympy.external import import_module
from sympy.testing.pytest import ignore_warnings, raises

antlr4 = import_module("antlr4", warn_not_installed=False)

# disable tests if antlr4-python3-runtime is not present
if antlr4:
    disabled = True


def test_no_import():
    from sympy.parsing.latex import parse_latex

    with ignore_warnings(UserWarning):
        with raises(ImportError):
            parse_latex('1 + 1')