Deprecate unused \*args to print_<foo>.

These `*args` are never used.

gtk3agg's print_png can just be directly inherited from agg (likely, it
is a remnant of a time when gtk3 would rely on cairo's png output by
default).

For the pgf backend, `*args` can be directly deleted because it would
previously have caused exceptions when forwarded to _print_pgf_to_fh.

Author: anntzer

doc/api/next_api_changes/deprecations/19487-AL.rst

@@ -0,0 +1,6 @@
+Unused positional parameters to ``print_<fmt>`` methods are deprecated
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+None of the ``print_<fmt>`` methods implemented by canvas subclasses used
+positional arguments other that the first (the output filename or file-like),
+so these extra parameters are deprecated.

lib/matplotlib/backends/backend_agg.py

@@ -448,6 +448,7 @@ def buffer_rgba(self):
         return self.renderer.buffer_rgba()
 
     @_check_savefig_extra_args
+    @_api.delete_parameter("3.5", "args")
     def print_raw(self, filename_or_obj, *args):
         FigureCanvasAgg.draw(self)
         renderer = self.get_renderer()
@@ -457,6 +458,7 @@ def print_raw(self, filename_or_obj, *args):
     print_rgba = print_raw
 
     @_check_savefig_extra_args
+    @_api.delete_parameter("3.5", "args")
     def print_png(self, filename_or_obj, *args,
                   metadata=None, pil_kwargs=None):
         """
@@ -528,6 +530,7 @@ def print_to_buffer(self):
                            alternative="pil_kwargs={'optimize': ...}")
     @_api.delete_parameter("3.3", "progressive",
                            alternative="pil_kwargs={'progressive': ...}")
+    @_api.delete_parameter("3.5", "args")
     def print_jpg(self, filename_or_obj, *args, pil_kwargs=None, **kwargs):
         """
         Write the figure to a JPEG file.

lib/matplotlib/backends/backend_gtk3agg.py

@@ -70,11 +70,6 @@ def draw(self):
         backend_agg.FigureCanvasAgg.draw(self)
         super().draw()
 
-    def print_png(self, filename, *args, **kwargs):
-        # Do this so we can save the resolution of figure in the PNG file
-        agg = self.switch_backends(backend_agg.FigureCanvasAgg)
-        return agg.print_png(filename, *args, **kwargs)
-
 
 class FigureManagerGTK3Agg(backend_gtk3.FigureManagerGTK3):
     pass

lib/matplotlib/backends/backend_pgf.py

@@ -843,17 +843,17 @@ def _print_pgf_to_fh(self, fh, *, bbox_inches_restore=None):
         writeln(fh, r"\makeatother")
         writeln(fh, r"\endgroup")
 
-    def print_pgf(self, fname_or_fh, *args, **kwargs):
+    def print_pgf(self, fname_or_fh, **kwargs):
         """
         Output pgf macros for drawing the figure so it can be included and
         rendered in latex documents.
         """
         with cbook.open_file_cm(fname_or_fh, "w", encoding="utf-8") as file:
             if not cbook.file_requires_unicode(file):
                 file = codecs.getwriter("utf-8")(file)
-            self._print_pgf_to_fh(file, *args, **kwargs)
+            self._print_pgf_to_fh(file, **kwargs)
 
-    def print_pdf(self, fname_or_fh, *args, metadata=None, **kwargs):
+    def print_pdf(self, fname_or_fh, *, metadata=None, **kwargs):
         """Use LaTeX to compile a pgf generated figure to pdf."""
         w, h = self.figure.get_figwidth(), self.figure.get_figheight()
 
@@ -865,7 +865,7 @@ def print_pdf(self, fname_or_fh, *args, metadata=None, **kwargs):
             tmppath = pathlib.Path(tmpdir)
 
             # print figure to pgf and compile it with latex
-            self.print_pgf(tmppath / "figure.pgf", *args, **kwargs)
+            self.print_pgf(tmppath / "figure.pgf", **kwargs)
 
             latexcode = """
 \\PassOptionsToPackage{pdfinfo={%s}}{hyperref}
@@ -891,14 +891,14 @@ def print_pdf(self, fname_or_fh, *args, metadata=None, **kwargs):
                  cbook.open_file_cm(fname_or_fh, "wb") as dest:
                 shutil.copyfileobj(orig, dest)  # copy file contents to target
 
-    def print_png(self, fname_or_fh, *args, **kwargs):
+    def print_png(self, fname_or_fh, **kwargs):
         """Use LaTeX to compile a pgf figure to pdf and convert it to png."""
         converter = make_pdf_to_png_converter()
         with TemporaryDirectory() as tmpdir:
             tmppath = pathlib.Path(tmpdir)
             pdf_path = tmppath / "figure.pdf"
             png_path = tmppath / "figure.png"
-            self.print_pdf(pdf_path, *args, **kwargs)
+            self.print_pdf(pdf_path, **kwargs)
             converter(pdf_path, png_path, dpi=self.figure.dpi)
             with png_path.open("rb") as orig, \
                  cbook.open_file_cm(fname_or_fh, "wb") as dest:

lib/matplotlib/backends/backend_ps.py

@@ -823,15 +823,17 @@ class FigureCanvasPS(FigureCanvasBase):
     def get_default_filetype(self):
         return 'ps'
 
+    @_api.delete_parameter("3.5", "args")
     def print_ps(self, outfile, *args, **kwargs):
-        return self._print_ps(outfile, 'ps', *args, **kwargs)
+        return self._print_ps(outfile, 'ps', **kwargs)
 
+    @_api.delete_parameter("3.5", "args")
     def print_eps(self, outfile, *args, **kwargs):
-        return self._print_ps(outfile, 'eps', *args, **kwargs)
+        return self._print_ps(outfile, 'eps', **kwargs)
 
     @_api.delete_parameter("3.4", "dpi")
     def _print_ps(
-            self, outfile, format, *args,
+            self, outfile, format, *,
             dpi=None, metadata=None, papertype=None, orientation='portrait',
             **kwargs):
 

lib/matplotlib/backends/backend_svg.py

@@ -1286,6 +1286,7 @@ class FigureCanvasSVG(FigureCanvasBase):
 
     fixed_dpi = 72
 
+    @_api.delete_parameter("3.5", "args")
     def print_svg(self, filename, *args, **kwargs):
         """
         Parameters
@@ -1337,6 +1338,7 @@ def print_svg(self, filename, *args, **kwargs):
             if detach:
                 fh.detach()
 
+    @_api.delete_parameter("3.5", "args")
     def print_svgz(self, filename, *args, **kwargs):
         with cbook.open_file_cm(filename, "wb") as fh, \
                 gzip.GzipFile(mode='w', fileobj=fh) as gzipwriter:

lib/matplotlib/backends/backend_template.py

@@ -29,6 +29,7 @@
     plt.savefig("figure.xyz")
 """
 
+from matplotlib import _api
 from matplotlib._pylab_helpers import Gcf
 from matplotlib.backend_bases import (
      FigureCanvasBase, FigureManagerBase, GraphicsContextBase, RendererBase)
@@ -209,6 +210,7 @@ def draw(self):
     # you should add it to the class-scope filetypes dictionary as follows:
     filetypes = {**FigureCanvasBase.filetypes, 'foo': 'My magic Foo format'}
 
+    @_api.delete_parameter("3.5", "args")
     def print_foo(self, filename, *args, **kwargs):
         """
         Write out format foo.