Replace isStringType(t) with isinstance(t, str)

Co-Authored-By: Jon Dufresne <jon.dufresne@gmail.com>

Tests/test_util.py

@@ -4,26 +4,6 @@ from .helper import PillowTestCase, unittest
 
 
 class TestUtil(PillowTestCase):
-    def test_is_string_type(self):
-        # Arrange
-        color = "red"
-
-        # Act
-        it_is = _util.isStringType(color)
-
-        # Assert
-        self.assertTrue(it_is)
-
-    def test_is_not_string_type(self):
-        # Arrange
-        color = (255, 0, 0)
-
-        # Act
-        it_is_not = _util.isStringType(color)
-
-        # Assert
-        self.assertFalse(it_is_not)
-
     def test_is_path(self):
         # Arrange
         fp = "filename.ext"

src/PIL/Image.py

@@ -43,7 +43,7 @@ from pathlib import Path
 # Use __version__ instead.
 from . import ImageMode, TiffTags, __version__, _plugins
 from ._binary import i8, i32le
-from ._util import deferred_error, isPath, isStringType
+from ._util import deferred_error, isPath
 
 logger = logging.getLogger(__name__)
 
@@ -1466,7 +1466,7 @@ class Image:
                 raise ValueError("cannot determine region size; use 4-item box")
             box += (box[0] + size[0], box[1] + size[1])
 
-        if isStringType(im):
+        if isinstance(im, str):
             from . import ImageColor
 
             im = ImageColor.getcolor(im, self.mode)
@@ -2120,7 +2120,7 @@ class Image:
         """
         self.load()
 
-        if isStringType(channel):
+        if isinstance(channel, str):
             try:
                 channel = self.getbands().index(channel)
             except ValueError:
@@ -2447,7 +2447,7 @@ def new(mode, size, color=0):
         # don't initialize
         return Image()._new(core.new(mode, size))
 
-    if isStringType(color):
+    if isinstance(color, str):
         # css3-style specifier
 
         from . import ImageColor

src/PIL/ImageCms.py

@@ -18,7 +18,6 @@
 import sys
 
 from PIL import Image
-from PIL._util import isStringType
 
 try:
     from PIL import _imagingcms
@@ -159,7 +158,7 @@ class ImageCmsProfile:
 
         """
 
-        if isStringType(profile):
+        if isinstance(profile, str):
             self._set(core.profile_open(profile), profile)
         elif hasattr(profile, "read"):
             self._set(core.profile_frombytes(profile.read()))

src/PIL/ImageDraw.py

@@ -34,7 +34,6 @@ import math
 import numbers
 
 from . import Image, ImageColor
-from ._util import isStringType
 
 
 """
@@ -107,13 +106,13 @@ class ImageDraw:
                 ink = self.ink
         else:
             if ink is not None:
-                if isStringType(ink):
+                if isinstance(ink, str):
                     ink = ImageColor.getcolor(ink, self.mode)
                 if self.palette and not isinstance(ink, numbers.Number):
                     ink = self.palette.getcolor(ink)
                 ink = self.draw.draw_ink(ink)
             if fill is not None:
-                if isStringType(fill):
+                if isinstance(fill, str):
                     fill = ImageColor.getcolor(fill, self.mode)
                 if self.palette and not isinstance(fill, numbers.Number):
                     fill = self.palette.getcolor(fill)

src/PIL/ImageOps.py

@@ -21,7 +21,6 @@ import functools
 import operator
 
 from . import Image
-from ._util import isStringType
 
 #
 # helpers
@@ -39,7 +38,7 @@ def _border(border):
 
 
 def _color(color, mode):
-    if isStringType(color):
+    if isinstance(color, str):
         from . import ImageColor
 
         color = ImageColor.getcolor(color, mode)

src/PIL/JpegImagePlugin.py

@@ -41,7 +41,6 @@ import warnings
 
 from . import Image, ImageFile, TiffImagePlugin
 from ._binary import i8, i16be as i16, i32be as i32, o8
-from ._util import isStringType
 from .JpegPresets import presets
 
 # __version__ is deprecated and will be removed in a future version. Use
@@ -638,7 +637,7 @@ def _save(im, fp, filename):
     else:
         if subsampling in presets:
             subsampling = presets[subsampling].get("subsampling", -1)
-        if isStringType(qtables) and qtables in presets:
+        if isinstance(qtables, str) and qtables in presets:
             qtables = presets[qtables].get("quantization")
 
     if subsampling == "4:4:4":
@@ -659,7 +658,7 @@ def _save(im, fp, filename):
     def validate_qtables(qtables):
         if qtables is None:
             return qtables
-        if isStringType(qtables):
+        if isinstance(qtables, str):
             try:
                 lines = [
                     int(num)

src/PIL/_util.py

@@ -4,10 +4,6 @@ import sys
 py36 = sys.version_info[0:2] >= (3, 6)
 
 
-def isStringType(t):
-    return isinstance(t, str)
-
-
 if py36:
     from pathlib import Path