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Abseil Team
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Add flags.override_value.
PiperOrigin-RevId: 572695699
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‎CHANGELOG.md

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@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com).
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## Unreleased
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### Added
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* (flags) Added `absl.flags.override_value` function to provide `FlagHolder`
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with a construct to modify values. The new interface parallels
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`absl.flags.FlagValues.__setattr__` but checks that the provided value
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conforms to the flag's expected type.
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### Fixed
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* The flag `foo` no longer retains the value `bar` after `FLAGS.foo = bar`
@@ -30,9 +37,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com).
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* (testing) `absltest.TestCase.assertSameStructure()` now uses the test case's
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equality functions (registered with `TestCase.addTypeEqualityFunc()`) for
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comparing leaves of the structure.
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* (testing) `abslTest.TestCase.fail()` now names its arguments
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`(self, msg=None, user_msg=None)`, and not `(self, msg=None, prefix=None)`,
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better reflecting the behavior and usage of the two message arguments.
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* (testing) `abslTest.TestCase.fail()` now names its arguments `(self,
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msg=None, user_msg=None)`, and not `(self, msg=None, prefix=None)`, better
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reflecting the behavior and usage of the two message arguments.
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* `DEFINE_enum`, `DEFINE_multi_enum`, and `EnumParser` now raise errors when
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`enum_values` is provided as a single string value. Additionally,
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`EnumParser.enum_values` is now stored as a list copy of the provided

‎absl/flags/__init__.py

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@@ -70,6 +70,7 @@
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'mark_bool_flags_as_mutual_exclusive',
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# Flag modifiers.
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'set_default',
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'override_value',
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# Key flag related functions.
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'declare_key_flag',
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'adopt_module_key_flags',
@@ -156,6 +157,7 @@
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# Flag modifiers.
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set_default = _defines.set_default
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override_value = _defines.override_value
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# Key flag related functions.
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declare_key_flag = _defines.declare_key_flag

‎absl/flags/_defines.py

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Original file line numberDiff line numberDiff line change
@@ -212,6 +212,31 @@ def set_default(flag_holder: _flagvalues.FlagHolder[_T], value: _T) -> None:
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flag_holder._flagvalues.set_default(flag_holder.name, value) # pylint: disable=protected-access
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def override_value(flag_holder: _flagvalues.FlagHolder[_T], value: _T) -> None:
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"""Overrides the value of the provided flag.
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This value takes precedent over the default value and, when called after flag
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parsing, any value provided at the command line.
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Args:
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flag_holder: FlagHolder, the flag to modify.
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value: The new value.
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Raises:
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IllegalFlagValueError: The value did not pass the flag parser or validators.
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"""
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fv = flag_holder._flagvalues # pylint: disable=protected-access
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# Ensure the new value satisfies the flag's parser while avoiding side
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# effects of calling parse().
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parsed = fv[flag_holder.name]._parse(value) # pylint: disable=protected-access
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if parsed != value:
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raise _exceptions.IllegalFlagValueError(
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'flag %s: parsed value %r not equal to original %r'
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% (flag_holder.name, parsed, value)
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)
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setattr(fv, flag_holder.name, value)
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215240
def _internal_declare_key_flags(
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flag_names: List[str],
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flag_values: _flagvalues.FlagValues = _flagvalues.FLAGS,

‎absl/flags/tests/flags_test.py

Lines changed: 108 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2592,6 +2592,114 @@ def test_failure_on_type_protected_none_default(self):
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_ = int_holder.value # Will also fail on later access.
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25942594

2595+
class OverrideValueTest(absltest.TestCase):
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def setUp(self):
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super().setUp()
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self.flag_values = flags.FlagValues()
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def test_success(self):
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int_holder = flags.DEFINE_integer(
2603+
'an_int', 1, 'an int', flag_values=self.flag_values
2604+
)
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2606+
flags.override_value(int_holder, 2)
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self.flag_values.mark_as_parsed()
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2609+
self.assertEqual(int_holder.value, 2)
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2611+
def test_update_after_parse(self):
2612+
int_holder = flags.DEFINE_integer(
2613+
'an_int', 1, 'an int', flag_values=self.flag_values
2614+
)
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2616+
self.flag_values.mark_as_parsed()
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flags.override_value(int_holder, 2)
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self.assertEqual(int_holder.value, 2)
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def test_overrides_explicit_assignment(self):
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int_holder = flags.DEFINE_integer(
2623+
'an_int', 1, 'an int', flag_values=self.flag_values
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)
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self.flag_values.mark_as_parsed()
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self.flag_values.an_int = 3
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flags.override_value(int_holder, 2)
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self.assertEqual(int_holder.value, 2)
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def test_overriden_by_explicit_assignment(self):
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int_holder = flags.DEFINE_integer(
2634+
'an_int', 1, 'an int', flag_values=self.flag_values
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)
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self.flag_values.mark_as_parsed()
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flags.override_value(int_holder, 2)
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self.flag_values.an_int = 3
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2641+
self.assertEqual(int_holder.value, 3)
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def test_multi_flag(self):
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multi_holder = flags.DEFINE_multi_string(
2645+
'strs', [], 'some strs', flag_values=self.flag_values
2646+
)
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2648+
flags.override_value(multi_holder, ['a', 'b'])
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self.flag_values.mark_as_parsed()
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2651+
self.assertEqual(multi_holder.value, ['a', 'b'])
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def test_failure_on_invalid_type(self):
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int_holder = flags.DEFINE_integer(
2655+
'an_int', 1, 'an int', flag_values=self.flag_values
2656+
)
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self.flag_values.mark_as_parsed()
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with self.assertRaises(flags.IllegalFlagValueError):
2661+
flags.override_value(int_holder, 'a') # pytype: disable=wrong-arg-types
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self.assertEqual(int_holder.value, 1)
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def test_failure_on_unparsed_value(self):
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int_holder = flags.DEFINE_integer(
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'an_int', 1, 'an int', flag_values=self.flag_values
2668+
)
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2670+
self.flag_values.mark_as_parsed()
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2672+
with self.assertRaises(flags.IllegalFlagValueError):
2673+
flags.override_value(int_holder, '2') # pytype: disable=wrong-arg-types
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2675+
def test_failure_on_parser_rejection(self):
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int_holder = flags.DEFINE_integer(
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'an_int', 1, 'an int', flag_values=self.flag_values, upper_bound=5
2678+
)
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2680+
self.flag_values.mark_as_parsed()
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2682+
with self.assertRaises(flags.IllegalFlagValueError):
2683+
flags.override_value(int_holder, 6)
2684+
2685+
self.assertEqual(int_holder.value, 1)
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2687+
def test_failure_on_validator_rejection(self):
2688+
int_holder = flags.DEFINE_integer(
2689+
'an_int', 1, 'an int', flag_values=self.flag_values
2690+
)
2691+
flags.register_validator(
2692+
int_holder.name, lambda x: x < 5, flag_values=self.flag_values
2693+
)
2694+
2695+
self.flag_values.mark_as_parsed()
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2697+
with self.assertRaises(flags.IllegalFlagValueError):
2698+
flags.override_value(int_holder, 6)
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2700+
self.assertEqual(int_holder.value, 1)
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25952703
class KeyFlagsTest(absltest.TestCase):
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25972705
def setUp(self):

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