Fix flake8 issues

doc/examples/utilities-examples.py

@@ -1,22 +1,18 @@
+"""Example showing importing colormaps from on-disk files."""
 from trollimage import utilities as tu
 
-
-#
-#  Examples: importing colormaps 
-#
-filename='setvak.rgb'
+#  Examples: importing colormaps
+filename = 'setvak.rgb'
 my_cmap = tu.cmap_from_text(filename)
 print(my_cmap.colors)
 my_cmap_norm = tu.cmap_from_text(filename, norm=True)
 print(my_cmap_norm.colors)
-my_cmap_transp = tu.cmap_from_text(filename,norm=True, transparency=True)
+my_cmap_transp = tu.cmap_from_text(filename, norm=True, transparency=True)
 print(my_cmap_transp.colors)
-filename='hrv.rgb'
-my_cmap_hex = tu.cmap_from_text(filename,hex=True)
+filename = 'hrv.rgb'
+my_cmap_hex = tu.cmap_from_text(filename, hex=True)
 print(my_cmap_hex.colors)
 
-#
 #  Example: converting PIL to trollimage.Image
-#
 image = "pifn.png"
 timage = tu.pilimage2trollimage(image)

trollimage/utilities.py

@@ -7,102 +7,105 @@
 from trollimage.image import Image
 from PIL import Image as Pimage
 
+
 def _hex_to_rgb(value):
-    '''
-    _hex_to_rgb converts a string of 3 hex color values
-    into a tuple of decimal values
-    '''
+    """Convert a string of 3 hex color values into a tuple of decimal values."""
     value = value.lstrip('#')
     dec = int(value, 16)
-    return dec 
+    return dec
+
+
+def _text_to_rgb(value, norm=False, cat=1, tot=1, offset=0.5, hex=False):
+    """Take text line and convert to RGB color.
 
-def _text_to_rgb(value,norm=False,cat=1, tot=1,offset=0.5,hex=False):
-    '''
-    _text_to_rgb takes as input a string composed by 3 values in the range [0,255]
+    This takes as input a string composed by 3 values in the range [0,255]
     and returns a tuple of integers. If the parameters cat and tot are given,
     the function generates a transparency value for this color and returns a tuple
     of length 4.
     tot is the total number of colors in the colormap
     cat is the index of the current colour in the colormap
     if norm is set to True, the input values are normalized between 0 and 1.
-    '''
+    """
     tokens = value.split()
     if hex:
-            for i in range(len(tokens)):
-                tokens[i] = _hex_to_rgb(tokens[i]) 
-    transparency = float(cat)/float(tot)+offset
+        for i in range(len(tokens)):
+            tokens[i] = _hex_to_rgb(tokens[i])
+    transparency = float(cat) / float(tot) + offset
     if transparency > 1.0:
         transparency = 1.0
     if norm:
-        return (float(tokens[0])/255.0, float(tokens[1])/255.0, float(tokens[2])/255.0, transparency)
-    else:    
+        return (float(tokens[0]) / 255.0, float(tokens[1]) / 255.0, float(tokens[2]) / 255.0, transparency)
+    else:
         return (int(tokens[0]), int(tokens[1]), int(tokens[2]), int(round(transparency * 255.0)))
 
 
 def _make_cmap(colors, position=None, bit=False):
-    '''
-    _make_cmap takes a list of tuples which contain RGB values. The RGB
+    """Convert list of tuples into Colormap object.
+
+    This takes a list of tuples which contain RGB values. The RGB
     values may either be in 8-bit [0 to 255] (in which bit must be set to
     True when called) or arithmetic [0 to 1] (default). _make_cmap returns
     a cmap with equally spaced colors.
     Arrange your tuples so that the first color is the lowest value for the
     colorbar and the last is the highest.
     position contains values from 0 to 1 to dictate the location of each color.
-    '''
-    bit_rgb = np.linspace(0,1,256)
-    if position == None:
-        position = np.linspace(0,1,len(colors))
-    else:
-        if len(position) != len(colors):
-            sys.exit("position length must be the same as colors")
-        elif position[0] != 0 or position[-1] != 1:
-            sys.exit("position must start with 0 and end with 1")
+    """
+    if position is None:
+        position = np.linspace(0, 1, len(colors))
+    if len(position) != len(colors):
+        sys.exit("position length must be the same as colors")
+    elif position[0] != 0 or position[-1] != 1:
+        sys.exit("position must start with 0 and end with 1")
     palette = [(i, (float(r), float(g), float(b), float(a))) for
-    i, (r, g, b, a) in enumerate(colors)]
+               i, (r, g, b, a) in enumerate(colors)]
     cmap = Colormap(*palette)
     return cmap
 
 
 def cmap_from_text(filename, norm=False, transparency=False, hex=False):
-    '''
-    cmap_from_text takes as input a file that contains a colormap in text format
+    """Convert text file colormap to Colormap object.
+
+    This takes as input a file that contains a colormap in text format
     composed by lines with 3 values in the range [0,255] or [00,FF]
     and returns a tuple of integers. If the parameters cat and tot are given,
     the function generates a transparency value for this color and returns a tuple
     of length 4.
     tot is the total number of colors in the colormap
     cat is the index of the current colour in the colormap
     if norm is set to True, the input values are normalized between 0 and 1.
-    '''
-    lines = [line.rstrip('\n') for line in open(filename)] 
-    _colors=[]
+    """
+    lines = [line.rstrip('\n') for line in open(filename)]
+    _colors = []
     _tot = len(lines)
     _index = 1
     for i in lines:
         if transparency:
-            _colors.append(_text_to_rgb(i,norm=norm,cat=_index,tot=_tot,hex=hex))
+            _colors.append(_text_to_rgb(i, norm=norm, cat=_index, tot=_tot, hex=hex))
         else:
-            _colors.append(_text_to_rgb(i,norm=norm,hex=hex))
+            _colors.append(_text_to_rgb(i, norm=norm, hex=hex))
         _index = _index + 1
     return _make_cmap(_colors)
 
 
 def _image2array(filepath):
-    '''
+    """Extract individual R, G, and B channels from on-disk image file.
+
     Utility function that converts an image file in 3 np arrays
     that can be fed into geo_image.GeoImage in order to generate
     a PyTROLL GeoImage object.
-    '''
+    """
     im = Pimage.open(filepath).convert('RGB')
     (width, height) = im.size
-    _r = np.array(list(im.getdata(0)))/255.0
-    _g = np.array(list(im.getdata(1)))/255.0
-    _b = np.array(list(im.getdata(2)))/255.0
+    _r = np.array(list(im.getdata(0))) / 255.0
+    _g = np.array(list(im.getdata(1))) / 255.0
+    _b = np.array(list(im.getdata(2))) / 255.0
     _r = _r.reshape((height, width))
     _g = _g.reshape((height, width))
     _b = _b.reshape((height, width))
     return _r, _g, _b
 
+
 def pilimage2trollimage(pimage):
-    (r,g,b) = _image2array(pimage)
-    return Image((r,g,b), mode="RGB")
+    """Convert PIL Image to trollimage Image."""
+    (r, g, b) = _image2array(pimage)
+    return Image((r, g, b), mode="RGB")