Ulrich Eckhardt wrote:
Lie Ryan wrote:
On 12/4/2009 8:28 AM, Ulrich Eckhardt wrote:
I'm trying to write some code to diff two fonts. What I have is every
character (glyph) of the two fonts in a list. I know that the list is
sorted by the codepoints of the characters. What I'd like to ask is
whether there is a more elegant solution to the loop below or whether
there are any rough corners in my code (see below). Note that I'm
targeting Python 2, not 3 yet.
Use sets:
glyph_1 = set(font1.glyphs)
glyph_2 = set(font2.glyphs)
only_in_1 = glyph_1 - glyph_2
only_in_2 = glyph_2 - glyph_1
in_both = glyph_1 & glyph_2
that is assuming font1.glyphs's value are hashable.
Thinking about it, I perhaps should store the glyphs in a set from the
beginning. Question is, can I (perhaps by providing the right hash function)
sort them by their codepoint? I'll have to look at the docs...
Thank you for this nudge in the right direction!
For sets you need __hash__ and __eq__, and for sorting you need __lt__.
Here's a simple example:
class Glyph(object):
def __init__(self, codepoint):
self.codepoint = codepoint
def __hash__(self):
return self.codepoint
def __eq__(self, other):
return self.codepoint == other.codepoint
def __lt__(self, other):
return self.codepoint < other.codepoint
def __repr__(self):
return "Glyph(%s)" % self.codepoint
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