Finished the first functional implementation of the Schedule.

Improved unit tests, including doctests.
Added several methods to util to assist with date processing.

lib/SVG/Schedule.py

@@ -5,7 +5,7 @@ from dateutil.parser import parse
 from dateutil.relativedelta import relativedelta
 
 from SVG import Graph
-from util import grouper, date_range
+from util import grouper, date_range, divide_timedelta_float, TimeScale
 
 __all__ = ('Schedule')
 
@@ -141,8 +141,8 @@ class Schedule(Graph):
 		will probably not be discernable if both data sets are plotted on the same
 		graph, since d1 is too granular.
 		"""
-		# note, the only reason this method is overridden is to change the
-		#  docstring
+		# The ruby version does something different here, throwing out
+		#  any previously added data.
 		super(Schedule, self).add_data(data)
 
 	# copied from Bar
@@ -166,7 +166,7 @@ class Schedule(Graph):
 		data = conf['data']
 		triples = grouper(3, data)
 		
-		begin_dates, end_dates, labels = zip(*triples)
+		labels, begin_dates, end_dates = zip(*triples)
 		
 		begin_dates = map(self.parse_date, begin_dates)
 		end_dates = map(self.parse_date, end_dates)
@@ -174,7 +174,10 @@ class Schedule(Graph):
 		# reconstruct the triples in a new order
 		reordered_triples = zip(begin_dates, end_dates, labels)
 		
+		# because of the reordering, this will sort by begin_date
+		#  then end_date, then label.
 		reordered_triples.sort()
+		
 		conf['data'] = reordered_triples
 
 	def parse_date(self, date_string):
@@ -202,26 +205,34 @@ class Schedule(Graph):
 		return height / -2.0
 	
 	def get_y_labels(self):
-		data = self.data['data']
+		# ruby version uses the last data supplied
+		last = -1
+		data = self.data[last]['data']
 		begin_dates, start_dates, labels = zip(*data)
 		return labels
 	
 	def draw_data(self):
-		bar_gap = self.get_bar_gap()
+		bar_gap = self.get_bar_gap(self.get_field_height())
 		
-		subbar_height = self.field_height - bar_gap
+		subbar_height = self.get_field_height() - bar_gap
 		
-		y_mod = (subbar_height / 2) + (font_size / 2)
-		x_min,x_max,div = self.x_range()
+		y_mod = (subbar_height / 2) + (self.font_size / 2)
+		x_min,x_max,div = self._x_range()
 		x_range = x_max - x_min
-		scale = (float(self.graph_width) - self.font_size*2)
-		scale /= x_range
+		width = (float(self.graph_width) - self.font_size*2)
+		# time_scale
+		#scale /= x_range
+		scale = TimeScale(width, x_range)
+		
+		# ruby version uses the last data supplied
+		last = -1
+		data = self.data[last]['data']
 		
-		for index, (x_start, x_end, label) in enumerate(self.data['data']):
+		for index, (x_start, x_end, label) in enumerate(data):
 			count = index + 1 # index is 0-based, count is 1-based
-			y = self.graph_height - (self.field_height*count)
-			bar_width = (x_end-x_stant)*scale
-			bar_start = (x_start-x_min)*scale
+			y = self.graph_height - (self.get_field_height()*count)
+			bar_width = scale*(x_end-x_start)
+			bar_start = scale*(x_start-x_min)
 			
 			rect = self._create_element('rect', {
 				'x': str(bar_start),
@@ -310,17 +321,24 @@ class Schedule(Graph):
 """
 
 	def _x_range(self):
-		start_dates, end_dates, labels = zip(*self.data['data'])
+		# ruby version uses teh last data supplied
+		last = -1
+		data = self.data[last]['data']
+		
+		start_dates, end_dates, labels = zip(*data)
 		all_dates = start_dates + end_dates
 		max_value = max(all_dates)
 		if not self.min_x_value is None:
 			all_dates.append(self.min_x_value)
 		min_value = min(all_dates)
-		range = relativedelta(max_value, min_value)
-		right_pad = (range / 20.0) or relativedelta(days=10)
+		range = max_value - min_value
+		right_pad = divide_timedelta_float(range, 20.0) or relativedelta(days=10)
 		scale_range = (max_value + right_pad) - min_value
 		
-		scale_division = self.scale_x_divisions or (scale_range / 10.0)
+		#scale_division = self.scale_x_divisions or (scale_range / 10.0)
+		# todo, remove timescale_x_divisions and use scale_x_divisions only
+		# but as a time delta
+		scale_division = divide_timedelta_float(scale_range, 10.0)
 		
 		# this doesn't make sense, because x is a timescale
 		#if self.scale_x_integers:
@@ -330,24 +348,22 @@ class Schedule(Graph):
 	
 	def get_x_values(self):
 		x_min, x_max, scale_division = self._x_range()
-		if timescale_divisions:
+		if self.timescale_divisions:
 			pattern = re.compile('(\d+) ?(\w+)')
-			m = pattern.match(timescale_divisions)
+			m = pattern.match(self.timescale_divisions)
 			if not m:
-				raise ValueError, "Invalid timescale_divisions: %s" % timescale_divisions
+				raise ValueError, "Invalid timescale_divisions: %s" % self.timescale_divisions
 			
-			magnitude = int(m.groups(1))
-			units = m.groups(2)
+			magnitude = int(m.group(1))
+			units = m.group(2)
 			
 			parameter = self.lookup_relativedelta_parameter(units)
 			
 			delta = relativedelta(**{parameter:magnitude})
 			
-			return daterange(x_min, x_max, delta)
-		else:
-			# I think much of the code is assuming x is an integer (seconds)
-			#  The whole logic needs to be revisited for this purpose.
-			return range(x_min, x_max, scale_division)
+			scale_division = delta
+
+		return date_range(x_min, x_max, scale_division)
 
 	def lookup_relativedelta_parameter(self, unit_string):
 		from util import reverse_mapping, flatten_mapping

lib/SVG/__init__.py

@@ -365,7 +365,7 @@ Copyright © 2008 Jason R. Coombs
 		
 		if self.rotate_x_labels:
 			transform = 'rotate(90 %d %d) translate(0 -%d)' % \
-				(x, y-self.x_label_font_size, x_label_font_size/4)
+				(x, y-self.x_label_font_size, self.x_label_font_size/4)
 			text.setAttribute('transform', transform)
 			text.setAttribute('style', 'text-anchor: start')
 		else:
@@ -479,25 +479,25 @@ Copyright © 2008 Jason R. Coombs
 		raise NotImplementedError
 
 	def draw_x_title(self):
-			raise NotImplementedError
+		raise NotImplementedError
 
 	def draw_y_title(self):
-			x = self.y_title_font_size
-			if self.y_title_text_direction=='bt':
-					x += 3
-					rotate = -90
-			else:
-					x -= 3
-					rotate = 90
-			y = self.height / 2
-			text = self._create_element('text', {
-					'x': str(x),
-					'y': str(y),
-					'class': 'yAxisTitle',
-					})
-			text.appendChild(self._doc.createTextNode(self.y_title))
-			text.setAttribute('transform', 'rotate(%(rotate)d, %(x)s, %(y)s)' % vars())
-			self.root.appendChild(text)
+		x = self.y_title_font_size
+		if self.y_title_text_direction=='bt':
+				x += 3
+				rotate = -90
+		else:
+				x -= 3
+				rotate = 90
+		y = self.height / 2
+		text = self._create_element('text', {
+				'x': str(x),
+				'y': str(y),
+				'class': 'yAxisTitle',
+				})
+		text.appendChild(self._doc.createTextNode(self.y_title))
+		text.setAttribute('transform', 'rotate(%(rotate)d, %(x)s, %(y)s)' % vars())
+		self.root.appendChild(text)
 
 	def keys(self):
 		return map(itemgetter('title'), self.data)

lib/SVG/util.py

@@ -1,18 +1,24 @@
 #!python
 
 from itertools import chain, repeat, izip
+import datetime
 
 # from itertools recipes (python documentation)
 def grouper(n, iterable, padvalue=None):
-	"grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
+	"""
+	>>> tuple(grouper(3, 'abcdefg', 'x'))
+	(('a', 'b', 'c'), ('d', 'e', 'f'), ('g', 'x', 'x'))
+	"""
 	return izip(*[chain(iterable, repeat(padvalue, n-1))]*n)
 
 def reverse_mapping(mapping):
 	"""
 	For every key, value pair, return the mapping for the
 	equivalent value, key pair
+	>>> reverse_mapping({'a': 'b'}) == {'b': 'a'}
+	True
 	"""
-	keys, values = mapping.items()
+	keys, values = zip(*mapping.items())
 	return dict(zip(values, keys))
 
 def flatten_mapping(mapping):
@@ -33,17 +39,74 @@ def flatten_items(items):
 			yield (keys, value)
 
 def float_range(start=0, stop=None, step=1):
-	"Much like the built-in function range, but accepts floats"
+	"""
+	Much like the built-in function range, but accepts floats
+	>>> tuple(float_range(0, 9, 1.5))
+	(0.0, 1.5, 3.0, 4.5, 6.0, 7.5)
+	"""
 	start = float(start)
 	while start < stop:
 		yield start
 		start += step
 
 def date_range(start=None, stop=None, step=None):
-	"Much like the built-in function range, but works with floats"
-	if step is None: step = relativedelta(days=1)
+	"""
+	Much like the built-in function range, but works with dates
+	>>> my_range = tuple(date_range(datetime.datetime(2005,12,21), datetime.datetime(2005,12,25)))
+	>>> datetime.datetime(2005,12,21) in my_range
+	True
+	>>> datetime.datetime(2005,12,22) in my_range
+	True
+	>>> datetime.datetime(2005,12,25) in my_range
+	False
+	"""
+	if step is None: step = datetime.timedelta(days=1)
 	if start is None: start = datetime.datetime.now()
 	while start < stop:
 		yield start
 		start += step
-	
+
+# copied from jaraco.datetools
+def divide_timedelta_float(td, divisor):
+	"""
+	Meant to work around the limitation that Python datetime doesn't support
+	floats as divisors or multiplicands to datetime objects
+	>>> one_day = datetime.timedelta(days=1)
+	>>> half_day = datetime.timedelta(days=.5)
+	>>> divide_timedelta_float(one_day, 2.0) == half_day
+	True
+	>>> divide_timedelta_float(one_day, 2) == half_day
+	False
+	"""
+	# td is comprised of days, seconds, microseconds
+	dsm = [getattr(td, attr) for attr in ('days', 'seconds', 'microseconds')]
+	dsm = map(lambda elem: elem/divisor, dsm)
+	return datetime.timedelta(*dsm)
+
+def get_timedelta_total_microseconds(td):
+	seconds = td.days*86400 + td.seconds
+	microseconds = td.microseconds + seconds*(10**6)
+	return microseconds
+
+def divide_timedelta(td1, td2):
+	"""
+	Get the ratio of two timedeltas
+	>>> one_day = datetime.timedelta(days=1)
+	>>> one_hour = datetime.timedelta(hours=1)
+	>>> divide_timedelta(one_hour, one_day) == 1/24.0
+	True
+	"""
+	
+	td1_total = float(get_timedelta_total_microseconds(td1))
+	td2_total = float(get_timedelta_total_microseconds(td2))
+	return td1_total/td2_total
+
+class TimeScale(object):
+	"Describes a scale factor based on time instead of a scalar"
+	def __init__(self, width, range):
+		self.width = width
+		self.range = range
+
+	def __mul__(self, delta):
+		scale = divide_timedelta(delta, self.range)
+		return scale*self.width

setup.cfg

@@ -1,3 +1,6 @@
 [egg_info]
 tag_build = dev
-tag_svn_revision = true
+tag_svn_revision = true
+
+[nosetests]
+with-doctest=1

setup.py

@@ -29,5 +29,10 @@ SVG Charting library based on the Ruby SVG::Graph
 	],
 	entry_points = {
 	},
+	tests_require=[
+		'nose>=0.10',
+	],
+	test_suite = "nose.collector",
+	
 	)
 

test/testing.py

@@ -115,7 +115,7 @@ g = Schedule.Schedule(dict(
 	show_data_labels = True,
 	show_y_guidelines = False,
 	show_x_guidelines = True,
-	show_x_title = True,
+	# show_x_title = True, # not yet implemented
 	x_title = "Time",
 	show_y_title = False,
 	rotate_x_labels = True,

test/testing.rb

@@ -143,6 +143,10 @@ data1 = [
   "Psychology 101", "6/28/04", "8/9/04",
   "Acting 105", "7/7/04", "8/16/04"
   ]
+title2 = "Another Schedule"
+data2 = [
+	"Just one period", "5/19/04", "6/30/04"
+]
 
 g = SVG::Graph::Schedule.new( {
   :width => 640,
@@ -173,6 +177,10 @@ g.add_data(
   :data => data1,
   :title => "Data"
   )
+g.add_data(
+	:data => data2,
+	:title => title2
+)
 
 f = File.new('Schedule.rb.svg', 'w')
 f.write(g.burn())