Add a few type hints

Author: WhyNotHugo

barcode/ean.py

@@ -42,7 +42,11 @@ class EuropeanArticleNumber13(Barcode):
     digits = 12
 
     def __init__(
-        self, ean: str, writer=None, no_checksum=False, guardbar=False
+        self,
+        ean: str,
+        writer=None,
+        no_checksum: bool = False,
+        guardbar: bool = False,
     ) -> None:
         if not ean[: self.digits].isdigit():
             raise IllegalCharacterError(f"EAN code can only contain numbers {ean}.")
@@ -121,7 +125,7 @@ def to_ascii(self) -> str:
         code = code_list[0]
         return code.replace("G", "|").replace("1", "|").replace("0", " ")
 
-    def render(self, writer_options=None, text=None):
+    def render(self, writer_options: dict | None = None, text: str | None = None):
         options = {"module_width": SIZES["SC2"]}
         options.update(writer_options or {})
         return super().render(options, text)
@@ -161,11 +165,8 @@ def __init__(self, jan, *args, **kwargs) -> None:
 class EuropeanArticleNumber8(EuropeanArticleNumber13):
     """Represents an EAN-8 barcode. See EAN13's __init__ for details.
 
-    :parameters:
-        ean : String
-            The ean number as string.
-        writer : barcode.writer Instance
-            The writer to render the barcode (default: SVGWriter).
+    :param ean: The ean number as string.
+    :param writer: The writer to render the barcode (default: SVGWriter).
     """
 
     name = "EAN-8"
@@ -197,7 +198,13 @@ class EuropeanArticleNumber8WithGuard(EuropeanArticleNumber8):
 
     name = "EAN-8 with guards"
 
-    def __init__(self, ean, writer=None, no_checksum=False, guardbar=True) -> None:
+    def __init__(
+        self,
+        ean: str,
+        writer=None,
+        no_checksum: bool = False,
+        guardbar: bool = True,
+    ) -> None:
         super().__init__(ean, writer, no_checksum, guardbar)
 
 

barcode/writer.py

@@ -50,12 +50,15 @@ def pt2mm(pt: float) -> float:
     return pt * 0.352777778
 
 
-def _set_attributes(element, **attributes):
+def _set_attributes(
+    element: xml.dom.minidom.Element,
+    **attributes: str,
+) -> None:
     for key, value in attributes.items():
         element.setAttribute(key, value)
 
 
-def create_svg_object(with_doctype=False) -> xml.dom.minidom.Document:
+def create_svg_object(with_doctype: bool = False) -> xml.dom.minidom.Document:
     imp = xml.dom.minidom.getDOMImplementation()
     assert imp is not None
     doctype = imp.createDocumentType(
@@ -64,6 +67,7 @@ def create_svg_object(with_doctype=False) -> xml.dom.minidom.Document:
         "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd",
     )
     document = imp.createDocument(None, "svg", doctype if with_doctype else None)
+    assert document.documentElement is not None
     _set_attributes(
         document.documentElement, version="1.1", xmlns="http://www.w3.org/2000/svg"
     )
@@ -385,7 +389,7 @@ def _create_text(self, xpos, ypos):
             self._group.appendChild(element)
             ypos += pt2mm(self.font_size) + self.text_line_distance
 
-    def _finish(self):
+    def _finish(self) -> bytes:
         if self.compress:
             return self._document.toxml(encoding="UTF-8")
 
@@ -422,7 +426,12 @@ class ImageWriter(BaseWriter):  # type: ignore[no-redef]
         mode: str
         dpi: int
 
-        def __init__(self, format="PNG", mode="RGB", dpi=300) -> None:
+        def __init__(
+            self,
+            format: str = "PNG",
+            mode: str = "RGB",
+            dpi: int = 300,
+        ) -> None:
             """Initialise a new write instance.
 
             :params format: The file format for the generated image. This parameter can