Expose API for setting the global "show errors in reprs" flag

python/pydantic_core/__init__.py

@@ -23,6 +23,7 @@
     ValidationError,
     __version__,
     from_json,
+    set_errors_include_url,
     to_json,
     to_jsonable_python,
     validate_core_schema,
@@ -65,6 +66,7 @@
     'TzInfo',
     'to_json',
     'from_json',
+    'set_errors_include_url',
     'to_jsonable_python',
     'validate_core_schema',
 ]

python/pydantic_core/_pydantic_core.pyi

@@ -849,6 +849,16 @@ def list_all_errors() -> list[ErrorTypeInfo]:
     Returns:
         A list of `ErrorTypeInfo` typed dicts.
     """
+
+def set_errors_include_url(flag: bool) -> None:
+    """
+    Set whether `repr`s of errors should include URLs to documentation on the error.
+
+    Defaults to `true` unless the `PYDANTIC_ERRORS_OMIT_URL` is set.
+
+    Args:
+        flag: Whether to include URLs in error `repr`s.
+    """
 @final
 class TzInfo(datetime.tzinfo):
     def tzname(self, _dt: datetime.datetime | None) -> str | None: ...

src/errors/mod.rs

@@ -9,7 +9,7 @@ mod value_exception;
 pub use self::line_error::{AsErrorValue, InputValue, ValError, ValLineError, ValResult};
 pub use self::location::{AsLocItem, LocItem};
 pub use self::types::{list_all_errors, ErrorType, ErrorTypeDefaults, Number};
-pub use self::validation_exception::ValidationError;
+pub use self::validation_exception::{set_errors_include_url, ValidationError};
 pub use self::value_exception::{PydanticCustomError, PydanticKnownError, PydanticOmit, PydanticUseDefault};
 
 pub fn py_err_string(py: Python, err: PyErr) -> String {

src/errors/validation_exception.rs

@@ -1,12 +1,13 @@
+use std::cell::RefCell;
 use std::fmt;
 use std::fmt::{Display, Write};
 use std::str::from_utf8;
 
 use pyo3::exceptions::{PyKeyError, PyTypeError, PyValueError};
 use pyo3::ffi;
 use pyo3::intern;
-use pyo3::once_cell::GILOnceCell;
 use pyo3::prelude::*;
+use pyo3::sync::{GILOnceCell, GILProtected};
 use pyo3::types::{PyDict, PyList, PyString};
 use serde::ser::{Error, SerializeMap, SerializeSeq};
 use serde::{Serialize, Serializer};
@@ -85,7 +86,7 @@ impl ValidationError {
     }
 
     pub fn display(&self, py: Python, prefix_override: Option<&'static str>, hide_input: bool) -> String {
-        let url_prefix = get_url_prefix(py, include_url_env(py));
+        let url_prefix = get_url_prefix(py, include_url(py));
         let line_errors = pretty_py_line_errors(py, self.input_type, self.line_errors.iter(), url_prefix, hide_input);
         if let Some(prefix) = prefix_override {
             format!("{prefix}\n{line_errors}")
@@ -191,17 +192,24 @@ impl ValidationError {
     }
 }
 
-static URL_ENV_VAR: GILOnceCell<bool> = GILOnceCell::new();
+static INCLUDE_URL_FLAG: GILProtected<RefCell<Option<bool>>> = GILProtected::new(RefCell::new(None));
 
-fn _get_include_url_env() -> bool {
-    match std::env::var("PYDANTIC_ERRORS_OMIT_URL") {
+fn include_url(py: Python) -> bool {
+    if let Some(flag) = *INCLUDE_URL_FLAG.get(py).borrow() {
+        return flag;
+    }
+    // If uninitialized, initialize from environment variable.
+    let flag = match std::env::var("PYDANTIC_ERRORS_OMIT_URL") {
         Ok(val) => val.is_empty(),
         Err(_) => true,
-    }
+    };
+    INCLUDE_URL_FLAG.get(py).borrow_mut().replace(flag);
+    flag
 }
 
-fn include_url_env(py: Python) -> bool {
-    *URL_ENV_VAR.get_or_init(py, _get_include_url_env)
+#[pyfunction]
+pub fn set_errors_include_url(py: Python, flag: bool) {
+    INCLUDE_URL_FLAG.get(py).borrow_mut().replace(flag);
 }
 
 static URL_PREFIX: GILOnceCell<String> = GILOnceCell::new();

src/lib.rs

@@ -29,7 +29,8 @@ pub use self::url::{PyMultiHostUrl, PyUrl};
 pub use argument_markers::{ArgsKwargs, PydanticUndefinedType};
 pub use build_tools::SchemaError;
 pub use errors::{
-    list_all_errors, PydanticCustomError, PydanticKnownError, PydanticOmit, PydanticUseDefault, ValidationError,
+    list_all_errors, set_errors_include_url, PydanticCustomError, PydanticKnownError, PydanticOmit, PydanticUseDefault,
+    ValidationError,
 };
 pub use serializers::{
     to_json, to_jsonable_python, PydanticSerializationError, PydanticSerializationUnexpectedValue, SchemaSerializer,
@@ -110,6 +111,7 @@ fn _pydantic_core(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(from_json, m)?)?;
     m.add_function(wrap_pyfunction!(to_jsonable_python, m)?)?;
     m.add_function(wrap_pyfunction!(list_all_errors, m)?)?;
+    m.add_function(wrap_pyfunction!(set_errors_include_url, m)?)?;
     m.add_function(wrap_pyfunction!(validate_core_schema, m)?)?;
     Ok(())
 }

tests/test_errors.py

@@ -16,6 +16,7 @@
     SchemaValidator,
     ValidationError,
     core_schema,
+    set_errors_include_url,
 )
 from pydantic_core._pydantic_core import list_all_errors
 
@@ -1074,3 +1075,14 @@ def test_hide_input_in_json() -> None:
 
     for error in exc_info.value.errors(include_input=False):
         assert 'input' not in error
+
+
+def test_hide_url_in_repr() -> None:
+    s = SchemaValidator({'type': 'int'})
+    with pytest.raises(ValidationError) as exc_info:
+        s.validate_python('definitely not an int')
+
+    set_errors_include_url(False)
+    assert 'https' not in repr(exc_info.value)
+    set_errors_include_url(True)
+    assert 'https' in repr(exc_info.value)