Upgrade Python syntax for 3.6+

Co-authored-by: nulano <[email protected]>

Tests/bench_cffi_access.py

@@ -28,15 +28,17 @@ def timer(func, label, *args):
         func(*args)
         if time.time() - starttime > 10:
             print(
-                "%s: breaking at %s iterations, %.6f per iteration"
-                % (label, x + 1, (time.time() - starttime) / (x + 1.0))
+                "{}: breaking at {} iterations, {:.6f} per iteration".format(
+                    label, x + 1, (time.time() - starttime) / (x + 1.0)
+                )
             )
             break
     if x == iterations - 1:
         endtime = time.time()
         print(
-            "%s: %.4f s  %.6f per iteration"
-            % (label, endtime - starttime, (endtime - starttime) / (x + 1.0))
+            "{}: {:.4f} s  {:.6f} per iteration".format(
+                label, endtime - starttime, (endtime - starttime) / (x + 1.0)
+            )
         )
 
 

Tests/check_imaging_leaks.py

@@ -25,7 +25,7 @@ def _test_leak(min_iterations, max_iterations, fn, *args, **kwargs):
         if i < min_iterations:
             mem_limit = mem + 1
             continue
-        msg = "memory usage limit exceeded after %d iterations" % (i + 1)
+        msg = f"memory usage limit exceeded after {i + 1} iterations"
         assert mem <= mem_limit, msg
 
 

Tests/check_png_dos.py

@@ -42,8 +42,8 @@ def test_dos_total_memory():
     info = PngImagePlugin.PngInfo()
 
     for x in range(64):
-        info.add_text("t%s" % x, compressed_data, zip=True)
-        info.add_itxt("i%s" % x, compressed_data, zip=True)
+        info.add_text(f"t{x}", compressed_data, zip=True)
+        info.add_itxt(f"i{x}", compressed_data, zip=True)
 
     b = BytesIO()
     im.save(b, "PNG", pnginfo=info)

Tests/conftest.py

@@ -9,4 +9,4 @@ def pytest_report_header(config):
             features.pilinfo(out=out, supported_formats=False)
             return out.getvalue()
     except Exception as e:
-        return "pytest_report_header failed: %s" % e
+        return f"pytest_report_header failed: {e}"

Tests/createfontdatachunk.py

@@ -6,7 +6,7 @@
     # create font data chunk for embedding
     font = "Tests/images/courB08"
     print("    f._load_pilfont_data(")
-    print("         # %s" % os.path.basename(font))
+    print(f"         # {os.path.basename(font)}")
     print("         BytesIO(base64.decodestring(b'''")
     with open(font + ".pil", "rb") as fp:
         print(base64.b64encode(fp.read()).decode())

Tests/helper.py

@@ -67,37 +67,31 @@ def convert_to_comparable(a, b):
 
 def assert_deep_equal(a, b, msg=None):
     try:
-        assert len(a) == len(b), msg or "got length {}, expected {}".format(
-            len(a), len(b)
-        )
+        assert len(a) == len(b), msg or f"got length {len(a)}, expected {len(b)}"
     except Exception:
         assert a == b, msg
 
 
 def assert_image(im, mode, size, msg=None):
     if mode is not None:
-        assert im.mode == mode, msg or "got mode {!r}, expected {!r}".format(
-            im.mode, mode
+        assert im.mode == mode, (
+            msg or f"got mode {repr(im.mode)}, expected {repr(mode)}"
         )
 
     if size is not None:
-        assert im.size == size, msg or "got size {!r}, expected {!r}".format(
-            im.size, size
+        assert im.size == size, (
+            msg or f"got size {repr(im.size)}, expected {repr(size)}"
         )
 
 
 def assert_image_equal(a, b, msg=None):
-    assert a.mode == b.mode, msg or "got mode {!r}, expected {!r}".format(
-        a.mode, b.mode
-    )
-    assert a.size == b.size, msg or "got size {!r}, expected {!r}".format(
-        a.size, b.size
-    )
+    assert a.mode == b.mode, msg or f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
+    assert a.size == b.size, msg or f"got size {repr(a.size)}, expected {repr(b.size)}"
     if a.tobytes() != b.tobytes():
         if HAS_UPLOADER:
             try:
                 url = test_image_results.upload(a, b)
-                logger.error("Url for test images: %s" % url)
+                logger.error(f"Url for test images: {url}")
             except Exception:
                 pass
 
@@ -112,12 +106,8 @@ def assert_image_equal_tofile(a, filename, msg=None, mode=None):
 
 
 def assert_image_similar(a, b, epsilon, msg=None):
-    assert a.mode == b.mode, msg or "got mode {!r}, expected {!r}".format(
-        a.mode, b.mode
-    )
-    assert a.size == b.size, msg or "got size {!r}, expected {!r}".format(
-        a.size, b.size
-    )
+    assert a.mode == b.mode, msg or f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
+    assert a.size == b.size, msg or f"got size {repr(a.size)}, expected {repr(b.size)}"
 
     a, b = convert_to_comparable(a, b)
 
@@ -129,13 +119,14 @@ def assert_image_similar(a, b, epsilon, msg=None):
     ave_diff = diff / (a.size[0] * a.size[1])
     try:
         assert epsilon >= ave_diff, (
-            msg or ""
-        ) + " average pixel value difference %.4f > epsilon %.4f" % (ave_diff, epsilon)
+            (msg or "")
+            + f" average pixel value difference {ave_diff:.4f} > epsilon {epsilon:.4f}"
+        )
     except Exception as e:
         if HAS_UPLOADER:
             try:
                 url = test_image_results.upload(a, b)
-                logger.error("Url for test images: %s" % url)
+                logger.error(f"Url for test images: {url}")
             except Exception:
                 pass
         raise e
@@ -166,7 +157,7 @@ def assert_tuple_approx_equal(actuals, targets, threshold, msg):
 
 
 def skip_unless_feature(feature):
-    reason = "%s not available" % feature
+    reason = f"{feature} not available"
     return pytest.mark.skipif(not features.check(feature), reason=reason)
 
 
@@ -204,7 +195,7 @@ def _test_leak(self, core):
         for cycle in range(self.iterations):
             core()
             mem = self._get_mem_usage() - start_mem
-            msg = "memory usage limit exceeded in iteration %d" % cycle
+            msg = f"memory usage limit exceeded in iteration {cycle}"
             assert mem < self.mem_limit, msg
 
 

Tests/test_bmp_reference.py

@@ -49,7 +49,7 @@ def test_questionable():
             with Image.open(f) as im:
                 im.load()
             if os.path.basename(f) not in supported:
-                print("Please add %s to the partially supported bmp specs." % f)
+                print(f"Please add {f} to the partially supported bmp specs.")
         except Exception:  # as msg:
             if os.path.basename(f) in supported:
                 raise
@@ -84,7 +84,7 @@ def get_compare(f):
         if name in file_map:
             return os.path.join(base, "html", file_map[name])
         name = os.path.splitext(name)[0]
-        return os.path.join(base, "html", "%s.png" % name)
+        return os.path.join(base, "html", f"{name}.png")
 
     for f in get_files("g"):
         try:
@@ -107,4 +107,4 @@ def get_compare(f):
                 os.path.join(base, "g", "pal8rle.bmp"),
                 os.path.join(base, "g", "pal4rle.bmp"),
             )
-            assert f in unsupported, "Unsupported Image {}: {}".format(f, msg)
+            assert f in unsupported, f"Unsupported Image {f}: {msg}"

Tests/test_file_apng.py

@@ -311,7 +311,7 @@ def test_apng_sequence_errors():
     ]
     for f in test_files:
         with pytest.raises(SyntaxError):
-            with Image.open("Tests/images/apng/{0}".format(f)) as im:
+            with Image.open(f"Tests/images/apng/{f}") as im:
                 im.seek(im.n_frames - 1)
                 im.load()
 

Tests/test_file_libtiff.py

@@ -173,18 +173,18 @@ def test_write_metadata(self, tmp_path):
                             assert (
                                 c_float(val[0][0] / val[0][1]).value
                                 == c_float(value[0][0] / value[0][1]).value
-                            ), ("%s didn't roundtrip" % tag)
+                            ), f"{tag} didn't roundtrip"
                         else:
-                            assert c_float(val).value == c_float(value).value, (
-                                "%s didn't roundtrip" % tag
-                            )
+                            assert (
+                                c_float(val).value == c_float(value).value
+                            ), f"{tag} didn't roundtrip"
                     else:
-                        assert val == value, "%s didn't roundtrip" % tag
+                        assert val == value, f"{tag} didn't roundtrip"
 
             # https://github.com/python-pillow/Pillow/issues/1561
             requested_fields = ["StripByteCounts", "RowsPerStrip", "StripOffsets"]
             for field in requested_fields:
-                assert field in reloaded, "%s not in metadata" % field
+                assert field in reloaded, f"{field} not in metadata"
 
     def test_additional_metadata(self, tmp_path):
         # these should not crash. Seriously dummy data, most of it doesn't make

Tests/test_file_sun.py

@@ -45,7 +45,7 @@ def test_others():
         with Image.open(path) as im:
             im.load()
             assert isinstance(im, SunImagePlugin.SunImageFile)
-            target_path = "%s.png" % os.path.splitext(path)[0]
+            target_path = f"{os.path.splitext(path)[0]}.png"
             # im.save(target_file)
             with Image.open(target_path) as target:
                 assert_image_equal(im, target)

Tests/test_file_tga.py

@@ -35,9 +35,7 @@ def roundtrip(original_im):
 
                 assert_image_equal(saved_im, original_im)
 
-        png_paths = glob(
-            os.path.join(_TGA_DIR_COMMON, "*x*_{}.png".format(mode.lower()))
-        )
+        png_paths = glob(os.path.join(_TGA_DIR_COMMON, f"*x*_{mode.lower()}.png"))
 
         for png_path in png_paths:
             with Image.open(png_path) as reference_im:

Tests/test_file_tiff_metadata.py

@@ -144,16 +144,16 @@ def test_write_metadata(tmp_path):
             assert_deep_equal(
                 original[tag],
                 value,
-                "{} didn't roundtrip, {}, {}".format(tag, original[tag], value),
+                f"{tag} didn't roundtrip, {original[tag]}, {value}",
             )
         else:
-            assert original[tag] == value, "{} didn't roundtrip, {}, {}".format(
-                tag, original[tag], value
-            )
+            assert (
+                original[tag] == value
+            ), f"{tag} didn't roundtrip, {original[tag]}, {value}"
 
     for tag, value in original.items():
         if tag not in ignored:
-            assert value == reloaded[tag], "%s didn't roundtrip" % tag
+            assert value == reloaded[tag], f"{tag} didn't roundtrip"
 
 
 def test_change_stripbytecounts_tag_type(tmp_path):

Tests/test_font_pcf_charsets.py

@@ -47,11 +47,11 @@ def delete_tempfile():
     font.save(tempname)
 
     with Image.open(tempname.replace(".pil", ".pbm")) as loaded:
-        with Image.open("Tests/fonts/ter-x20b-%s.pbm" % encoding) as target:
+        with Image.open(f"Tests/fonts/ter-x20b-{encoding}.pbm") as target:
             assert_image_equal(loaded, target)
 
     with open(tempname, "rb") as f_loaded:
-        with open("Tests/fonts/ter-x20b-%s.pil" % encoding, "rb") as f_target:
+        with open(f"Tests/fonts/ter-x20b-{encoding}.pil", "rb") as f_target:
             assert f_loaded.read() == f_target.read()
     return tempname
 

Tests/test_image_access.py

@@ -125,14 +125,13 @@ def check(self, mode, c=None):
         im.putpixel((0, 0), c)
         assert (
             im.getpixel((0, 0)) == c
-        ), "put/getpixel roundtrip failed for mode {}, color {}".format(mode, c)
+        ), f"put/getpixel roundtrip failed for mode {mode}, color {c}"
 
         # check putpixel negative index
         im.putpixel((-1, -1), c)
-        assert im.getpixel((-1, -1)) == c, (
-            "put/getpixel roundtrip negative index failed for mode %s, color %s"
-            % (mode, c)
-        )
+        assert (
+            im.getpixel((-1, -1)) == c
+        ), f"put/getpixel roundtrip negative index failed for mode {mode}, color {c}"
 
         # Check 0
         im = Image.new(mode, (0, 0), None)
@@ -150,11 +149,11 @@ def check(self, mode, c=None):
         im = Image.new(mode, (1, 1), c)
         assert (
             im.getpixel((0, 0)) == c
-        ), "initial color failed for mode {}, color {} ".format(mode, c)
+        ), f"initial color failed for mode {mode}, color {c} "
         # check initial color negative index
         assert (
             im.getpixel((-1, -1)) == c
-        ), "initial color failed with negative index for mode %s, color %s " % (mode, c)
+        ), f"initial color failed with negative index for mode {mode}, color {c} "
 
         # Check 0
         im = Image.new(mode, (0, 0), c)

Tests/test_image_reduce.py

@@ -161,8 +161,8 @@ def compare_reduce_with_reference(im, factor, average_diff=0.4, max_diff=1):
 
 
 def assert_compare_images(a, b, max_average_diff, max_diff=255):
-    assert a.mode == b.mode, "got mode %r, expected %r" % (a.mode, b.mode)
-    assert a.size == b.size, "got size %r, expected %r" % (a.size, b.size)
+    assert a.mode == b.mode, f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
+    assert a.size == b.size, f"got size {repr(a.size)}, expected {repr(b.size)}"
 
     a, b = convert_to_comparable(a, b)
 
@@ -175,16 +175,15 @@ def assert_compare_images(a, b, max_average_diff, max_diff=255):
             a.size[0] * a.size[1]
         )
         msg = (
-            "average pixel value difference {:.4f} > expected {:.4f} "
-            "for '{}' band".format(average_diff, max_average_diff, band)
+            f"average pixel value difference {average_diff:.4f} > "
+            f"expected {max_average_diff:.4f} for '{band}' band"
         )
         assert max_average_diff >= average_diff, msg
 
         last_diff = [i for i, num in enumerate(ch_hist) if num > 0][-1]
-        assert (
-            max_diff >= last_diff
-        ), "max pixel value difference {} > expected {} for '{}' band".format(
-            last_diff, max_diff, band
+        assert max_diff >= last_diff, (
+            f"max pixel value difference {last_diff} > expected {max_diff} "
+            f"for '{band}' band"
         )