Remove Python 3.7 support

.coin-or/projDesc.xml

@@ -287,7 +287,7 @@ Carl D. Laird, Chair, Pyomo Management Committee, claird at andrew dot cmu dot e
 
 			<platform>
 				<operatingSystem>Any</operatingSystem>
-				<compiler>Python 3.7, 3.8, 3.9, 3.10, 3.11</compiler>
+				<compiler>Python 3.8, 3.9, 3.10, 3.11</compiler>
 			</platform>
 
 		</testedPlatforms>

.github/workflows/release_wheel_creation.yml

@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        wheel-version: ['cp37-cp37m', 'cp38-cp38', 'cp39-cp39', 'cp310-cp310', 'cp311-cp311']
+        wheel-version: ['cp38-cp38', 'cp39-cp39', 'cp310-cp310', 'cp311-cp311']
         os: [ubuntu-latest]
         include:
         - os: ubuntu-latest
@@ -102,7 +102,7 @@ jobs:
         include:
         - os: macos-latest
           TARGET: osx
-        python-version: [ 3.7, 3.8, 3.9, '3.10', '3.11' ]
+        python-version: [ 3.8, 3.9, '3.10', '3.11' ]
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}
@@ -133,7 +133,7 @@ jobs:
         include:
         - os: windows-latest
           TARGET: win
-        python-version: [ 3.7, 3.8, 3.9, '3.10', '3.11' ]
+        python-version: [ 3.8, 3.9, '3.10', '3.11' ]
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}

.github/workflows/test_pr_and_main.yml

@@ -56,7 +56,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python: [3.7, 3.8, 3.9, '3.10', '3.11']
+        python: [ 3.8, 3.9, '3.10', '3.11' ]
         other: [""]
         category: [""]
 
@@ -83,7 +83,7 @@ jobs:
           PACKAGES:
 
         - os: ubuntu-latest
-          python: 3.8
+          python: 3.9
           other: /mpi
           mpi: 3
           skip_doctest: 1
@@ -116,15 +116,15 @@ jobs:
           PYENV: pip
 
         - os: ubuntu-latest
-          python: 3.7
+          python: 3.8
           other: /slim
           slim: 1
           skip_doctest: 1
           TARGET: linux
           PYENV: pip
 
         - os: ubuntu-latest
-          python: 3.8
+          python: 3.9
           other: /pyutilib
           TARGET: linux
           PYENV: pip

README.md

@@ -51,7 +51,7 @@ Pyomo is available under the BSD License - see the
 
 Pyomo is currently tested with the following Python implementations:
 
-* CPython: 3.7, 3.8, 3.9, 3.10, 3.11
+* CPython: 3.8, 3.9, 3.10, 3.11
 * PyPy: 3.7, 3.8, 3.9
 
 _Testing and support policy_:

doc/OnlineDocs/installation.rst

@@ -3,7 +3,7 @@ Installation
 
 Pyomo currently supports the following versions of Python:
 
-* CPython: 3.7, 3.8, 3.9, 3.10, 3.11
+* CPython: 3.8, 3.9, 3.10, 3.11
 * PyPy: 3
 
 At the time of the first Pyomo release after the end-of-life of a minor Python

pyomo/common/plugin_base.py

@@ -16,21 +16,12 @@
 #  the U.S. Government retains certain rights in this software.
 #  ___________________________________________________________________________
 
-import collections
 import inspect
-import sys
 from weakref import ref as weakref_ref
 
 from pyomo.common.errors import PyomoException
 from pyomo.common.deprecation import deprecated, deprecation_warning
 
-if sys.version_info[:2] >= (3, 7):
-    _deterministic_dict = dict
-else:
-    from pyomo.common.collections import OrderedDict
-
-    _deterministic_dict = OrderedDict
-
 
 class PluginGlobals(object):
     @staticmethod
@@ -206,7 +197,7 @@ def __new__(cls, name, bases, classdict, *args, **kwargs):
 
         # Register the new class with the interfaces
         for interface, inherit, service in implements:
-            interface._plugins[new_class] = _deterministic_dict()
+            interface._plugins[new_class] = {}
             interface._aliases.update({name: (new_class, doc) for name, doc in aliases})
 
         if _singleton:

pyomo/common/tests/test_deprecated.py

@@ -11,8 +11,6 @@
 #
 """Testing for deprecated function."""
 import sys
-import types
-import weakref
 
 import pyomo.common.unittest as unittest
 
@@ -368,10 +366,6 @@ def test_relocated_class(self):
 
         from pyomo.common.tests import relocated
 
-        if sys.version_info < (3, 5):
-            # Make sure that the module is only wrapped once
-            self.assertIs(type(relocated._wrapped_module), types.ModuleType)
-
         self.assertNotIn('Foo', dir(relocated))
         self.assertNotIn('Foo_2', dir(relocated))
 
@@ -414,8 +408,7 @@ def test_relocated_class(self):
             "(?:'module' object) has no attribute 'Baz'",
         ):
             relocated.Baz.data
-        if sys.version_info[:2] >= (3, 7):
-            self.assertEqual(relocated.Foo_3, '_3')
+        self.assertEqual(relocated.Foo_3, '_3')
 
         with self.assertRaisesRegex(
             AttributeError,

pyomo/common/tests/test_fileutils.py

@@ -229,15 +229,6 @@ def test_findfile(self):
             os.path.join(subdir, subdir_name),
         )
 
-    # TODO: Remove this when Python 3.7 is no longer supported
-    @unittest.skipIf(
-        sys.version_info[:2] < (3, 8)
-        and (
-            platform.mac_ver()[0].startswith('10.16')
-            or platform.mac_ver()[0].startswith('12.6')
-        ),
-        "find_library has known bugs in Big Sur/Monterey for Python<3.8",
-    )
     def test_find_library_system(self):
         # Find a system library (before we muck with the PATH)
         _args = {'cwd': False, 'include_PATH': False, 'pathlist': []}

pyomo/contrib/incidence_analysis/incidence.py

@@ -10,11 +10,12 @@
 #  ___________________________________________________________________________
 """Functionality for identifying variables that participate in expressions
 """
-import enum
+
+from contextlib import nullcontext
+
 from pyomo.core.expr.visitor import identify_variables
 from pyomo.core.expr.numvalue import value as pyo_value
 from pyomo.repn import generate_standard_repn
-from pyomo.common.backports import nullcontext
 from pyomo.util.subsystems import TemporarySubsystemManager
 from pyomo.contrib.incidence_analysis.config import IncidenceMethod, IncidenceConfig
 

pyomo/core/base/set.py

@@ -68,8 +68,6 @@
 
 logger = logging.getLogger('pyomo.core')
 
-_prePython37 = sys.version_info[:2] < (3, 7)
-
 _inf = float('inf')
 
 FLATTEN_CROSS_PRODUCT = True
@@ -1950,8 +1948,6 @@ class SortedOrder(object):
 
     _ValidOrderedAuguments = {True, False, InsertionOrder, SortedOrder}
     _UnorderedInitializers = {set}
-    if _prePython37:
-        _UnorderedInitializers.add(dict)
 
     def __new__(cls, *args, **kwds):
         if cls is not Set:

pyomo/core/expr/expr_common.py

@@ -10,8 +10,8 @@
 #  ___________________________________________________________________________
 
 import enum
+from contextlib import nullcontext
 
-from pyomo.common.backports import nullcontext
 from pyomo.common.deprecation import deprecated
 
 TO_STRING_VERBOSE = False

pyomo/core/expr/template_expr.py

@@ -9,13 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-import copy
 import itertools
 import logging
 import sys
 import builtins
+from contextlib import nullcontext
 
-from pyomo.common.backports import nullcontext
 from pyomo.common.errors import TemplateExpressionError
 from pyomo.core.expr.base import ExpressionBase, ExpressionArgs_Mixin, NPV_Mixin
 from pyomo.core.expr.logical_expr import BooleanExpression
@@ -25,6 +24,7 @@
     Numeric_NPV_Mixin,
     register_arg_type,
     ARG_TYPE,
+    _balanced_parens,
 )
 from pyomo.core.expr.numvalue import (
     NumericValue,

pyomo/environ/tests/test_environ.py

@@ -92,9 +92,6 @@ def test_not_auto_imported(self):
                 "pyomo.environ and it should not."
             )
 
-    @unittest.skipIf(
-        sys.version_info[:2] < (3, 7), "Import timing introduced in python 3.7"
-    )
     @unittest.skipIf(
         'pypy_version_info' in dir(sys), "PyPy does not support '-X importtime"
     )

pyomo/opt/solver/shellcmd.py

@@ -17,8 +17,8 @@
 import logging
 import subprocess
 from io import StringIO
+from contextlib import nullcontext
 
-from pyomo.common.backports import nullcontext
 from pyomo.common.errors import ApplicationError
 from pyomo.common.collections import Bunch
 from pyomo.common.log import is_debug_set, LoggingIntercept

pyomo/repn/plugins/baron_writer.py

@@ -17,8 +17,8 @@
 import logging
 import math
 from io import StringIO
+from contextlib import nullcontext
 
-from pyomo.common.backports import nullcontext
 from pyomo.common.collections import OrderedSet
 from pyomo.opt import ProblemFormat
 from pyomo.opt.base import AbstractProblemWriter, WriterFactory

pyomo/repn/plugins/nl_writer.py

@@ -13,8 +13,8 @@
 import os
 from collections import deque
 from operator import itemgetter, attrgetter, setitem
+from contextlib import nullcontext
 
-from pyomo.common.backports import nullcontext
 from pyomo.common.config import (
     ConfigBlock,
     ConfigValue,

pyomo/repn/util.py

@@ -65,15 +65,14 @@ class FileDeterminism(enum.IntEnum):
     SORT_SYMBOLS = 30
 
     # We will define __str__ and __format__ so that behavior in python
-    # 3.11 is consistent with 3.7 - 3.10.
+    # 3.11 is consistent with 3.8 - 3.10.
 
     def __str__(self):
         return enum.Enum.__str__(self)
 
     def __format__(self, spec):
-        # This cannot just call Enum.__format__ because that returns the
-        # numeric value in Python 3.7
-        return str(self).__format__(spec)
+        # Removal of Python 3.7 support allows us to use Enum.__format__
+        return enum.Enum.__format__(self, spec)
 
     @classmethod
     def _missing_(cls, value):

setup.py

@@ -207,7 +207,6 @@ def _print_deps(self, deplist):
         'Operating System :: Unix',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
         'Programming Language :: Python :: 3.10',
@@ -217,7 +216,7 @@ def _print_deps(self, deplist):
         'Topic :: Scientific/Engineering :: Mathematics',
         'Topic :: Software Development :: Libraries :: Python Modules',
     ],
-    python_requires='>=3.7',
+    python_requires='>=3.8',
     install_requires=['ply'],
     extras_require={
         'tests': [