From fe72e26f94cc40837e2bd15f5e782ae048ce3b5c Mon Sep 17 00:00:00 2001
From: Daniel Oelschlegel <amoibos@gmail.com>
Date: Thu, 1 May 2014 23:01:50 +0200
Subject: [PATCH] new style class definition performance improvements through
 using of list comprehension

---
 PIL/BmpImagePlugin.py |  3 +--
 PIL/Image.py          |  6 +++---
 PIL/ImageOps.py       | 29 +++++++----------------------
 PIL/ImagePalette.py   | 21 ++++++---------------
 PIL/ImagePath.py      |  2 +-
 PIL/ImageQt.py        |  6 ++----
 PIL/ImageSequence.py  |  2 +-
 PIL/ImageShow.py      |  4 ++--
 PIL/ImageStat.py      |  2 +-
 PIL/ImageTk.py        |  4 ++--
 PIL/ImageWin.py       |  8 ++++----
 PIL/PcxImagePlugin.py |  3 +--
 12 files changed, 31 insertions(+), 59 deletions(-)

diff --git a/PIL/BmpImagePlugin.py b/PIL/BmpImagePlugin.py
index cd6dc49a2..386010e50 100644
--- a/PIL/BmpImagePlugin.py
+++ b/PIL/BmpImagePlugin.py
@@ -232,8 +232,7 @@ def _save(im, fp, filename, check=0):
         for i in (0, 255):
             fp.write(o8(i) * 4)
     elif im.mode == "L":
-        for i in range(256):
-            fp.write(o8(i) * 4)
+        fp.write("".join(o8(i) * 4 for i in range(256)))
     elif im.mode == "P":
         fp.write(im.im.getpalette("RGB", "BGRX"))
 
diff --git a/PIL/Image.py b/PIL/Image.py
index 8d278317e..45480a7ee 100644
--- a/PIL/Image.py
+++ b/PIL/Image.py
@@ -233,7 +233,7 @@ _MODE_CONV = {
     "CMYK": ('|u1', 4),
     "YCbCr": ('|u1', 3),
     "LAB": ('|u1', 3), # UNDONE - unsigned |u1i1i1
-	# I;16 == I;16L, and I;32 == I;32L  
+    # I;16 == I;16L, and I;32 == I;32L  
     "I;16": ('<u2', None),
     "I;16B": ('>u2', None),
     "I;16L": ('<u2', None),
@@ -920,8 +920,8 @@ class Image:
 
         if box is None:
             return self.copy()
-	else:
-	    self.load()
+        else:
+            self.load()
         # lazy operation
         return _ImageCrop(self, box)
 
diff --git a/PIL/ImageOps.py b/PIL/ImageOps.py
index b0e35fa00..b7e6b6222 100644
--- a/PIL/ImageOps.py
+++ b/PIL/ImageOps.py
@@ -86,7 +86,7 @@ def autocontrast(image, cutoff=0, ignore=None):
             # get number of pixels
             n = 0
             for ix in range(256):
-                n = n + h[ix]
+                n += h[ix]
             # remove cutoff% pixels from the low end
             cut = n * cutoff // 100
             for lo in range(256):
@@ -147,13 +147,10 @@ def colorize(image, black, white):
     assert image.mode == "L"
     black = _color(black, "RGB")
     white = _color(white, "RGB")
-    red = []; green = []; blue = []
-    for i in range(256):
-        red.append(black[0]+i*(white[0]-black[0])//255)
-        green.append(black[1]+i*(white[1]-black[1])//255)
-        blue.append(black[2]+i*(white[2]-black[2])//255)
     image = image.convert("RGB")
-    return _lut(image, red + green + blue)
+    return _lut(image, ([black[0]+i*(white[0]-black[0])//255 for i in range(256)] +
+            [black[1]+i*(white[1]-black[1])//255 for i in range(256)] + 
+            [black[2]+i*(white[2]-black[2])//255 for i in range(256)]))
 
 
 def crop(image, border=0):
@@ -357,10 +354,7 @@ def invert(image):
     :param image: The image to invert.
     :return: An image.
     """
-    lut = []
-    for i in range(256):
-        lut.append(255-i)
-    return _lut(image, lut)
+    return _lut(image, [255 - i for i in range(256)])
 
 
 def mirror(image):
@@ -381,11 +375,8 @@ def posterize(image, bits):
     :param bits: The number of bits to keep for each channel (1-8).
     :return: An image.
     """
-    lut = []
     mask = ~(2**(8-bits)-1)
-    for i in range(256):
-        lut.append(i & mask)
-    return _lut(image, lut)
+    return _lut(image, [i & mask for i in range(256)])
 
 
 def solarize(image, threshold=128):
@@ -396,13 +387,7 @@ def solarize(image, threshold=128):
     :param threshold: All pixels above this greyscale level are inverted.
     :return: An image.
     """
-    lut = []
-    for i in range(256):
-        if i < threshold:
-            lut.append(i)
-        else:
-            lut.append(255-i)
-    return _lut(image, lut)
+    return _lut(image, [i if i < threshold else 255 - i for i in range(256)])
 
 # --------------------------------------------------------------------
 # PIL USM components, from Kevin Cazabon.
diff --git a/PIL/ImagePalette.py b/PIL/ImagePalette.py
index d5b9d04eb..61f639f0c 100644
--- a/PIL/ImagePalette.py
+++ b/PIL/ImagePalette.py
@@ -20,7 +20,7 @@ import array
 from PIL import Image, ImageColor
 
 
-class ImagePalette:
+class ImagePalette(object):
     "Color palette for palette mapped images"
 
     def __init__(self, mode = "RGB", palette = None, size = 0):
@@ -120,19 +120,12 @@ def raw(rawmode, data):
 # Factories
 
 def _make_linear_lut(black, white):
-    lut = []
-    if black == 0:
-        for i in range(256):
-            lut.append(white*i//255)
-    else:
+    if black != 0:
         raise NotImplementedError # FIXME
-    return lut
+    return [(white*i//255) for i in range(256)]
 
 def _make_gamma_lut(exp, mode="RGB"):
-    lut = []
-    for i in range(256):
-        lut.append(int(((i / 255.0) ** exp) * 255.0 + 0.5))
-    return lut
+    return [int(((i / 255.0) ** exp) * 255.0 + 0.5) for i in range(256)]
 
 def new(mode, data):
     return Image.core.new_palette(mode, data)
@@ -144,10 +137,8 @@ def negative(mode="RGB"):
 
 def random(mode="RGB"):
     from random import randint
-    palette = []
-    for i in range(256*len(mode)):
-        palette.append(randint(0, 255))
-    return ImagePalette(mode, palette)
+    
+    return ImagePalette(mode, [randint(0, 255) for i in range(256 * len(mode))])
 
 def sepia(white="#fff0c0"):
     r, g, b = ImageColor.getrgb(white)
diff --git a/PIL/ImagePath.py b/PIL/ImagePath.py
index 656d5ce61..f23d01430 100644
--- a/PIL/ImagePath.py
+++ b/PIL/ImagePath.py
@@ -20,7 +20,7 @@ from PIL import Image
 # the Python class below is overridden by the C implementation.
 
 
-class Path:
+class Path(object):
 
     def __init__(self, xy):
         pass
diff --git a/PIL/ImageQt.py b/PIL/ImageQt.py
index ca8b14b5c..4a27ff07a 100644
--- a/PIL/ImageQt.py
+++ b/PIL/ImageQt.py
@@ -30,7 +30,7 @@ except:
 def rgb(r, g, b, a=255):
     # use qRgb to pack the colors, and then turn the resulting long
     # into a negative integer with the same bitpattern.
-    return (qRgba(r, g, b, a) & 0xffffffff)
+    return qRgba(r, g, b, a) & 0xffffffff
 
 ##
 # An PIL image wrapper for Qt.  This is a subclass of PyQt4's QImage
@@ -57,9 +57,7 @@ class ImageQt(QImage):
             format = QImage.Format_Mono
         elif im.mode == "L":
             format = QImage.Format_Indexed8
-            colortable = []
-            for i in range(256):
-                colortable.append(rgb(i, i, i))
+            colortable = [rgb(i, i, i) for i in range(256)] 
         elif im.mode == "P":
             format = QImage.Format_Indexed8
             colortable = []
diff --git a/PIL/ImageSequence.py b/PIL/ImageSequence.py
index 513c9247b..cf28d9104 100644
--- a/PIL/ImageSequence.py
+++ b/PIL/ImageSequence.py
@@ -15,7 +15,7 @@
 
 ##
 
-class Iterator:
+class Iterator(object):
     """
     This class implements an iterator object that can be used to loop
     over an image sequence.
diff --git a/PIL/ImageShow.py b/PIL/ImageShow.py
index e81866bac..4f1676131 100644
--- a/PIL/ImageShow.py
+++ b/PIL/ImageShow.py
@@ -17,7 +17,7 @@ from __future__ import print_function
 from PIL import Image
 import os, sys
 
-if(sys.version_info >= (3, 3)):
+if sys.version_info >= (3, 3):
     from shlex import quote
 else:
     from pipes import quote
@@ -52,7 +52,7 @@ def show(image, title=None, **options):
 ##
 # Base class for viewers.
 
-class Viewer:
+class Viewer(object):
 
     # main api
 
diff --git a/PIL/ImageStat.py b/PIL/ImageStat.py
index ef63b7857..e5ba3070b 100644
--- a/PIL/ImageStat.py
+++ b/PIL/ImageStat.py
@@ -26,7 +26,7 @@ import operator, math
 from functools import reduce
 
 
-class Stat:
+class Stat(object):
 
     def __init__(self, image_or_list, mask = None):
         try:
diff --git a/PIL/ImageTk.py b/PIL/ImageTk.py
index 1e81d240e..22653c159 100644
--- a/PIL/ImageTk.py
+++ b/PIL/ImageTk.py
@@ -54,7 +54,7 @@ def _pilbitmap_check():
 # --------------------------------------------------------------------
 # PhotoImage
 
-class PhotoImage:
+class PhotoImage(object):
     """
     A Tkinter-compatible photo image.  This can be used
     everywhere Tkinter expects an image object.  If the image is an RGBA
@@ -192,7 +192,7 @@ class PhotoImage:
 # BitmapImage
 
 
-class BitmapImage:
+class BitmapImage(object):
     """
 
     A Tkinter-compatible bitmap image.  This can be used everywhere Tkinter
diff --git a/PIL/ImageWin.py b/PIL/ImageWin.py
index aa90b887b..caaca822f 100644
--- a/PIL/ImageWin.py
+++ b/PIL/ImageWin.py
@@ -21,7 +21,7 @@ import warnings
 from PIL import Image
 
 
-class HDC:
+class HDC(object):
     """
     Wraps a HDC integer. The resulting object can be passed to the
     :py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
@@ -32,7 +32,7 @@ class HDC:
     def __int__(self):
         return self.dc
 
-class HWND:
+class HWND(object):
     """
     Wraps a HWND integer. The resulting object can be passed to the
     :py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
@@ -44,7 +44,7 @@ class HWND:
         return self.wnd
 
 
-class Dib:
+class Dib(object):
     """
     A Windows bitmap with the given mode and size.  The mode can be one of "1",
     "L", "P", or "RGB".
@@ -207,7 +207,7 @@ class Dib:
 ##
 # Create a Window with the given title size.
 
-class Window:
+class Window(object):
 
     def __init__(self, title="PIL", width=None, height=None):
         self.hwnd = Image.core.createwindow(
diff --git a/PIL/PcxImagePlugin.py b/PIL/PcxImagePlugin.py
index 2496af676..c7025fecc 100644
--- a/PIL/PcxImagePlugin.py
+++ b/PIL/PcxImagePlugin.py
@@ -173,8 +173,7 @@ def _save(im, fp, filename, check=0):
     elif im.mode == "L":
         # greyscale palette
         fp.write(o8(12))
-        for i in range(256):
-            fp.write(o8(i)*3)
+        fp.write("".join(o8(i)*3 for i in range(256)))
 
 # --------------------------------------------------------------------
 # registry