Skip to content

Add regex patterns reflecting Decimal Constraints to the Decimal type's string schema #11420

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
Jack70248 wants to merge 11 commits into from
Closed

Add regex patterns reflecting Decimal Constraints to the Decimal type's string schema #11420

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
11 commits
Select commit Hold shift + click to select a range
1e916d4
Add decimal precision constraints to JSON schema
KCui0327 Dec 1, 2024
890850d
Addressed all feedbacks and added more test cases
KCui0327 Dec 6, 2024
f430c1b
Update decimal regex patterns and related logic in GenerateJsonSchema…
Jack70248 Feb 8, 2025
7014353
update tests and docs with new decimal constraint patterns
Jack70248 Feb 8, 2025
a67d5b9
Revert "update tests and docs with new decimal constraint patterns"
Jack70248 Feb 8, 2025
753b828
Update tests, add test cases to test various decimal regex patterns
Jack70248 Feb 8, 2025
6446895
Add guard so we don't add a pattern if both max_digits and decimal_pl…
Jack70248 Feb 8, 2025
fd366fa
Tidy up patterns, address coverage missing line
Jack70248 Feb 8, 2025
805c785
fix bug in max digit lookahead pattern
Jack70248 Feb 9, 2025
69a0e37
Allow for trailing zeroes in validation, refine when a max digit look…
Jack70248 Feb 22, 2025
88da428
fix trailing zero bug and simplify max_digit lookahead
Jack70248 Mar 11, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
63 changes: 62 additions & 1 deletion pydantic/json_schema.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,33 @@ class PydanticJsonSchemaWarning(UserWarning):
CoreModeRef = tuple[CoreRef, JsonSchemaMode]
JsonSchemaKeyT = TypeVar('JsonSchemaKeyT', bound=Hashable)

# ##### Regex for Decimal JSON Schema Generation #####

_DECIMAL_JSON_VALIDATION_MAX_DIGIT_LOOKAHEAD_PATTERN = (
r'(?=(?:\d(\.)?){{1,{max_digits}}}' # Positive lookahead for max_digits and optional decimal place
r'(?(1)0*)$)' # yes-pattern allowing trailing zeroes if the decimal place exists
)

_DECIMAL_JSON_SERIALIZATION_MAX_DIGIT_LOOKAHEAD_PATTERN = (
r'(?=(?:\d\.?){{1,{max_digits}}}$)' # Positive lookahead for max_digits and optional decimal place
)

_DECIMAL_JSON_VALIDATION_PATTERN = (
r'^-?' # Minus sign (optional)
r'0*' # Allow leading zeroes
r'{max_digit_lookahead}' # Substitution for max digit lookahead if required
r'\d{{1,{integer_places}}}' # One or more integer digits
r'(?:\.\d{{0,{decimal_places}}}0*)?' # Optional non-capturing group: decimal digits
r'$'
)

_DECIMAL_JSON_SERIALIZATION_PATTERN = (
r'^-?' # Minus sign (optional)
r'{max_digit_lookahead}' # Substitution for max digit lookahead if required
r'(?:0|[1-9]\d{{0,{integer_places}}})' # Non-capturing group: Single zero OR non-zero digit and integer digits
r'(?:\.\d{{0,{decimal_places}}})?$' # Optional non-capturing group: decimal digits
)


@dataclasses.dataclass(**_internal_dataclass.slots_true)
class _DefinitionsRemapping:
Expand Down Expand Up @@ -674,7 +701,41 @@ def decimal_schema(self, schema: core_schema.DecimalSchema) -> JsonSchemaValue:
Returns:
The generated JSON schema.
"""
json_schema = self.str_schema(core_schema.str_schema())
max_digits = schema.get('max_digits')
decimal_places = schema.get('decimal_places')
str_schema = core_schema.str_schema()
# Only add a pattern if either max_digits or decimal_places is set
if max_digits is not None or decimal_places is not None:
max_digit_lookahead = ''
if self.mode == 'validation':
# Only set a max digit lookahead if max_digits is set
if max_digits is not None:
max_digit_lookahead = _DECIMAL_JSON_VALIDATION_MAX_DIGIT_LOOKAHEAD_PATTERN.format(
max_digits=max_digits
)
integer_places = '' if max_digits is None or decimal_places is None else max_digits - decimal_places
decimal_regex_pattern = _DECIMAL_JSON_VALIDATION_PATTERN.format(
max_digit_lookahead=max_digit_lookahead,
integer_places=integer_places,
decimal_places='' if decimal_places is None else decimal_places,
)
str_schema['pattern'] = re.compile(decimal_regex_pattern).pattern
elif self.mode == 'serialization':
if max_digits is not None:
max_digit_lookahead = _DECIMAL_JSON_SERIALIZATION_MAX_DIGIT_LOOKAHEAD_PATTERN.format(
max_digits=max_digits
)
# For the serialization pattern we match the first integer digit separate from the rest, to account for
# this we want our integer_places argument to be one less than max_digits - decimal_places
integer_places = '' if max_digits is None or decimal_places is None else max_digits - decimal_places - 1
decimal_regex_pattern = _DECIMAL_JSON_SERIALIZATION_PATTERN.format(
max_digit_lookahead=max_digit_lookahead,
integer_places=integer_places,
decimal_places='' if decimal_places is None else decimal_places,
)
str_schema['pattern'] = re.compile(decimal_regex_pattern).pattern
json_schema = self.str_schema(str_schema)

if self.mode == 'validation':
multiple_of = schema.get('multiple_of')
le = schema.get('le')
Expand Down
48 changes: 48 additions & 0 deletions tests/test_json_schema.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2012,6 +2012,37 @@ class A(BaseModel):
({'ge': 2}, Decimal, {'anyOf': [{'type': 'number', 'minimum': 2}, {'type': 'string'}]}),
({'le': 5}, Decimal, {'anyOf': [{'type': 'number', 'maximum': 5}, {'type': 'string'}]}),
({'multiple_of': 5}, Decimal, {'anyOf': [{'type': 'number', 'multipleOf': 5}, {'type': 'string'}]}),
(
{'max_digits': 4},
Decimal,
{
'anyOf': [
{'type': 'number'},
{
'pattern': '^-?0*(?=(?:\\d(\\.)?){1,4}(?(1)0*)$)\\d{1,}(?:\\.\\d{0,}0*)?$',
'type': 'string',
},
]
},
),
(
{'decimal_places': 2},
Decimal,
{'anyOf': [{'type': 'number'}, {'pattern': '^-?0*\\d{1,}(?:\\.\\d{0,2}0*)?$', 'type': 'string'}]},
),
(
{'max_digits': 4, 'decimal_places': 2},
Decimal,
{
'anyOf': [
{'type': 'number'},
{
'pattern': '^-?0*(?=(?:\\d(\\.)?){1,4}(?(1)0*)$)\\d{1,2}(?:\\.\\d{0,2}0*)?$',
'type': 'string',
},
]
},
),
],
)
def test_constraints_schema_validation(kwargs, type_, expected_extra):
Expand Down Expand Up @@ -2055,6 +2086,23 @@ class Foo(BaseModel):
({'ge': 2}, Decimal, {'type': 'string'}),
({'le': 5}, Decimal, {'type': 'string'}),
({'multiple_of': 5}, Decimal, {'type': 'string'}),
(
{'max_digits': 4},
Decimal,
{
'pattern': '^-?(?=(?:\\d\\.?){1,4}$)(?:0|[1-9]\\d{0,})(?:\\.\\d{0,})?$',
'type': 'string',
},
),
({'decimal_places': 2}, Decimal, {'pattern': '^-?(?:0|[1-9]\\d{0,})(?:\\.\\d{0,2})?$', 'type': 'string'}),
(
{'max_digits': 4, 'decimal_places': 2},
Decimal,
{
'pattern': '^-?(?=(?:\\d\\.?){1,4}$)(?:0|[1-9]\\d{0,1})(?:\\.\\d{0,2})?$',
'type': 'string',
},
),
],
)
def test_constraints_schema_serialization(kwargs, type_, expected_extra):
Expand Down