1 files changed, 49 insertions, 0 deletions
diff --git a/venv/lib/python3.11/site-packages/faker/providers/sbn/sbn.py b/venv/lib/python3.11/site-packages/faker/providers/sbn/sbn.py
new file mode 100644
index 0000000..070f799
--- /dev/null
+++ b/venv/lib/python3.11/site-packages/faker/providers/sbn/sbn.py
@@ -0,0 +1,49 @@
+"""
+This module is responsible for generating the check digit and formatting
+SBN numbers.
+"""
+from typing import Any, Optional
+
+
+class SBN:
+    MAX_LENGTH = 9
+
+    def __init__(
+        self,
+        registrant: Optional[str] = None,
+        publication: Optional[str] = None,
+    ) -> None:
+        self.registrant = registrant
+        self.publication = publication
+
+
+class SBN9(SBN):
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        self.check_digit = self._check_digit()
+
+    def _check_digit(self) -> str:
+        """Calculate the check digit for SBN-9.
+        SBNs use the same check digit calculation as ISBN. See
+        https://en.wikipedia.org/wiki/International_Standard_Book_Number
+                for calculation. Only modification is weights range from 1 to 9
+                instead of 1 to 10.
+        """
+        weights = range(1, 9)
+        body = "".join([part for part in [self.registrant, self.publication] if part is not None])
+        remainder = sum(int(b) * w for b, w in zip(body, weights)) % 11
+        check_digit = "X" if remainder == 10 else str(remainder)
+        return str(check_digit)
+
+    def format(self, separator: str = "") -> str:
+        return separator.join(
+            [
+                part
+                for part in [
+                    self.registrant,
+                    self.publication,
+                    self.check_digit,
+                ]
+                if part is not None
+            ]
+        )