From 4d46106f8c233c5af283c903000ef8c6f1165393 Mon Sep 17 00:00:00 2001 From: Claude Paroz Date: Thu, 14 Jun 2012 15:24:47 +0200 Subject: [PATCH] Fixed #17754 -- Refactored gis.measure This refactoring does allow much easier MeasureBase subclassing. Many thanks to Ricardo di Virgilio for the initial patch. --- AUTHORS | 1 + django/contrib/gis/measure.py | 313 ++++++++++------------- django/contrib/gis/tests/test_measure.py | 6 +- 3 files changed, 142 insertions(+), 178 deletions(-) diff --git a/AUTHORS b/AUTHORS index ea23ca45d0..ea0b01926c 100644 --- a/AUTHORS +++ b/AUTHORS @@ -161,6 +161,7 @@ answer newbie questions, and generally made Django that much better: Rajesh Dhawan Sander Dijkhuis Jordan Dimov + Riccardo Di Virgilio Nebojša Dorđević dne@mayonnaise.net dready diff --git a/django/contrib/gis/measure.py b/django/contrib/gis/measure.py index 46e198c410..9efea504c7 100644 --- a/django/contrib/gis/measure.py +++ b/django/contrib/gis/measure.py @@ -30,7 +30,7 @@ Distance and Area objects to allow for sensible and convienient calculation and conversions. -Authors: Robert Coup, Justin Bronn +Authors: Robert Coup, Justin Bronn, Riccardo Di Virgilio Inspired by GeoPy (http://exogen.case.edu/projects/geopy/) and Geoff Biggs' PhD work on dimensioned units for robotics. @@ -40,13 +40,134 @@ from decimal import Decimal from django.utils.functional import total_ordering +NUMERIC_TYPES = (int, float, long, Decimal) +AREA_PREFIX = "sq_" + +def pretty_name(obj): + return obj.__name__ if obj.__class__ == type else obj.__class__.__name__ + + +@total_ordering class MeasureBase(object): + STANDARD_UNIT = None + ALIAS = {} + UNITS = {} + LALIAS = {} + + def __init__(self, default_unit=None, **kwargs): + value, self._default_unit = self.default_units(kwargs) + setattr(self, self.STANDARD_UNIT, value) + if default_unit and isinstance(default_unit, basestring): + self._default_unit = default_unit + + def _get_standard(self): + return getattr(self, self.STANDARD_UNIT) + + def _set_standard(self, value): + setattr(self, self.STANDARD_UNIT, value) + + standard = property(_get_standard, _set_standard) + + def __getattr__(self, name): + if name in self.UNITS: + return self.standard / self.UNITS[name] + else: + raise AttributeError('Unknown unit type: %s' % name) + + def __repr__(self): + return '%s(%s=%s)' % (pretty_name(self), self._default_unit, + getattr(self, self._default_unit)) + + def __str__(self): + return '%s %s' % (getattr(self, self._default_unit), self._default_unit) + + # **** Comparison methods **** + + def __eq__(self, other): + if isinstance(other, self.__class__): + return self.standard == other.standard + else: + return NotImplemented + + def __lt__(self, other): + if isinstance(other, self.__class__): + return self.standard < other.standard + else: + return NotImplemented + + # **** Operators methods **** + + def __add__(self, other): + if isinstance(other, self.__class__): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard + other.standard)}) + else: + raise TypeError('%(class)s must be added with %(class)s' % {"class":pretty_name(self)}) + + def __iadd__(self, other): + if isinstance(other, self.__class__): + self.standard += other.standard + return self + else: + raise TypeError('%(class)s must be added with %(class)s' % {"class":pretty_name(self)}) + + def __sub__(self, other): + if isinstance(other, self.__class__): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard - other.standard)}) + else: + raise TypeError('%(class)s must be subtracted from %(class)s' % {"class":pretty_name(self)}) + + def __isub__(self, other): + if isinstance(other, self.__class__): + self.standard -= other.standard + return self + else: + raise TypeError('%(class)s must be subtracted from %(class)s' % {"class":pretty_name(self)}) + + def __mul__(self, other): + if isinstance(other, NUMERIC_TYPES): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard * other)}) + else: + raise TypeError('%(class)s must be multiplied with number' % {"class":pretty_name(self)}) + + def __imul__(self, other): + if isinstance(other, NUMERIC_TYPES): + self.standard *= float(other) + return self + else: + raise TypeError('%(class)s must be multiplied with number' % {"class":pretty_name(self)}) + + def __rmul__(self, other): + return self * other + + def __div__(self, other): + if isinstance(other, self.__class__): + return self.standard / other.standard + if isinstance(other, NUMERIC_TYPES): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard / other)}) + else: + raise TypeError('%(class)s must be divided with number or %(class)s' % {"class":pretty_name(self)}) + + def __idiv__(self, other): + if isinstance(other, NUMERIC_TYPES): + self.standard /= float(other) + return self + else: + raise TypeError('%(class)s must be divided with number' % {"class":pretty_name(self)}) + + def __nonzero__(self): + return bool(self.standard) + def default_units(self, kwargs): """ Return the unit value and the default units specified from the given keyword arguments dictionary. """ val = 0.0 + default_unit = self.STANDARD_UNIT for unit, value in kwargs.iteritems(): if not isinstance(value, float): value = float(value) if unit in self.UNITS: @@ -86,8 +207,8 @@ class MeasureBase(object): else: raise Exception('Could not find a unit keyword associated with "%s"' % unit_str) -@total_ordering class Distance(MeasureBase): + STANDARD_UNIT = "m" UNITS = { 'chain' : 20.1168, 'chain_benoit' : 20.116782, @@ -163,189 +284,33 @@ class Distance(MeasureBase): } LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()]) - def __init__(self, default_unit=None, **kwargs): - # The base unit is in meters. - self.m, self._default_unit = self.default_units(kwargs) - if default_unit and isinstance(default_unit, str): - self._default_unit = default_unit - - def __getattr__(self, name): - if name in self.UNITS: - return self.m / self.UNITS[name] - else: - raise AttributeError('Unknown unit type: %s' % name) - - def __repr__(self): - return 'Distance(%s=%s)' % (self._default_unit, getattr(self, self._default_unit)) - - def __str__(self): - return '%s %s' % (getattr(self, self._default_unit), self._default_unit) - - def __eq__(self, other): - if isinstance(other, Distance): - return self.m == other.m - else: - return NotImplemented - - def __lt__(self, other): - if isinstance(other, Distance): - return self.m < other.m - else: - return NotImplemented - - def __add__(self, other): - if isinstance(other, Distance): - return Distance(default_unit=self._default_unit, m=(self.m + other.m)) - else: - raise TypeError('Distance must be added with Distance') - - def __iadd__(self, other): - if isinstance(other, Distance): - self.m += other.m - return self - else: - raise TypeError('Distance must be added with Distance') - - def __sub__(self, other): - if isinstance(other, Distance): - return Distance(default_unit=self._default_unit, m=(self.m - other.m)) - else: - raise TypeError('Distance must be subtracted from Distance') - - def __isub__(self, other): - if isinstance(other, Distance): - self.m -= other.m - return self - else: - raise TypeError('Distance must be subtracted from Distance') - def __mul__(self, other): - if isinstance(other, (int, float, long, Decimal)): - return Distance(default_unit=self._default_unit, m=(self.m * float(other))) - elif isinstance(other, Distance): - return Area(default_unit='sq_' + self._default_unit, sq_m=(self.m * other.m)) + if isinstance(other, self.__class__): + return Area(default_unit=AREA_PREFIX + self._default_unit, + **{AREA_PREFIX + self.STANDARD_UNIT: (self.standard * other.standard)}) + elif isinstance(other, NUMERIC_TYPES): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard * other)}) else: - raise TypeError('Distance must be multiplied with number or Distance') + raise TypeError('%(distance)s must be multiplied with number or %(distance)s' % { + "distance" : pretty_name(self.__class__), + }) - def __imul__(self, other): - if isinstance(other, (int, float, long, Decimal)): - self.m *= float(other) - return self - else: - raise TypeError('Distance must be multiplied with number') - def __rmul__(self, other): - return self * other - - def __div__(self, other): - if isinstance(other, (int, float, long, Decimal)): - return Distance(default_unit=self._default_unit, m=(self.m / float(other))) - else: - raise TypeError('Distance must be divided with number') - - def __idiv__(self, other): - if isinstance(other, (int, float, long, Decimal)): - self.m /= float(other) - return self - else: - raise TypeError('Distance must be divided with number') - - def __nonzero__(self): - return bool(self.m) - -@total_ordering class Area(MeasureBase): + STANDARD_UNIT = AREA_PREFIX + Distance.STANDARD_UNIT # Getting the square units values and the alias dictionary. - UNITS = dict([('sq_%s' % k, v ** 2) for k, v in Distance.UNITS.items()]) - ALIAS = dict([(k, 'sq_%s' % v) for k, v in Distance.ALIAS.items()]) + UNITS = dict([('%s%s' % (AREA_PREFIX, k), v ** 2) for k, v in Distance.UNITS.items()]) + ALIAS = dict([(k, '%s%s' % (AREA_PREFIX, v)) for k, v in Distance.ALIAS.items()]) LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()]) - def __init__(self, default_unit=None, **kwargs): - self.sq_m, self._default_unit = self.default_units(kwargs) - if default_unit and isinstance(default_unit, str): - self._default_unit = default_unit - - def __getattr__(self, name): - if name in self.UNITS: - return self.sq_m / self.UNITS[name] - else: - raise AttributeError('Unknown unit type: ' + name) - - def __repr__(self): - return 'Area(%s=%s)' % (self._default_unit, getattr(self, self._default_unit)) - - def __str__(self): - return '%s %s' % (getattr(self, self._default_unit), self._default_unit) - - def __eq__(self, other): - if isinstance(other, Area): - return self.sq_m == other.sq_m - else: - return NotImplemented - - def __lt__(self, other): - if isinstance(other, Area): - return self.sq_m < other.sq_m - else: - return NotImplemented - - def __add__(self, other): - if isinstance(other, Area): - return Area(default_unit=self._default_unit, sq_m=(self.sq_m + other.sq_m)) - else: - raise TypeError('Area must be added with Area') - - def __iadd__(self, other): - if isinstance(other, Area): - self.sq_m += other.sq_m - return self - else: - raise TypeError('Area must be added with Area') - - def __sub__(self, other): - if isinstance(other, Area): - return Area(default_unit=self._default_unit, sq_m=(self.sq_m - other.sq_m)) - else: - raise TypeError('Area must be subtracted from Area') - - def __isub__(self, other): - if isinstance(other, Area): - self.sq_m -= other.sq_m - return self - else: - raise TypeError('Area must be subtracted from Area') - - def __mul__(self, other): - if isinstance(other, (int, float, long, Decimal)): - return Area(default_unit=self._default_unit, sq_m=(self.sq_m * float(other))) - else: - raise TypeError('Area must be multiplied with number') - - def __imul__(self, other): - if isinstance(other, (int, float, long, Decimal)): - self.sq_m *= float(other) - return self - else: - raise TypeError('Area must be multiplied with number') - - def __rmul__(self, other): - return self * other - def __div__(self, other): - if isinstance(other, (int, float, long, Decimal)): - return Area(default_unit=self._default_unit, sq_m=(self.sq_m / float(other))) + if isinstance(other, NUMERIC_TYPES): + return self.__class__(default_unit=self._default_unit, + **{self.STANDARD_UNIT: (self.standard / other)}) else: - raise TypeError('Area must be divided with number') + raise TypeError('%(class)s must be divided by a number' % {"class":pretty_name(self)}) - def __idiv__(self, other): - if isinstance(other, (int, float, long, Decimal)): - self.sq_m /= float(other) - return self - else: - raise TypeError('Area must be divided with number') - - def __nonzero__(self): - return bool(self.sq_m) # Shortcuts D = Distance diff --git a/django/contrib/gis/tests/test_measure.py b/django/contrib/gis/tests/test_measure.py index f3325628b6..0428704d6c 100644 --- a/django/contrib/gis/tests/test_measure.py +++ b/django/contrib/gis/tests/test_measure.py @@ -93,6 +93,8 @@ class DistanceTest(unittest.TestCase): self.assertEqual(d4.m, 50) d4 /= 5 self.assertEqual(d4.m, 10) + d5 = d1 / D(m=2) + self.assertEqual(d5, 50) a5 = d1 * D(m=10) self.assertTrue(isinstance(a5, Area)) @@ -102,10 +104,6 @@ class DistanceTest(unittest.TestCase): d1 *= D(m=1) self.fail('Distance *= Distance should raise TypeError') - with self.assertRaises(TypeError): - d5 = d1 / D(m=1) - self.fail('Distance / Distance should raise TypeError') - with self.assertRaises(TypeError): d1 /= D(m=1) self.fail('Distance /= Distance should raise TypeError')