fix a critical conflict between registration of farads and Faradays. Registry will now raise an error when an attempt is made to register using a previously used key. Fixes bug #495181.

ddale · ddale · commit 124dab6ef0e5 · 2009-12-11T10:51:11.000-05:00
diff --git a/quantities/constants/electron.py b/quantities/constants/electron.py
@@ -17,7 +17,7 @@
     _cd('elementary charge over h'),
     symbol='e/h'
 )
-F = Faraday_constant = UnitConstant(
+Faraday_constant = UnitConstant(
     'Faraday_constant',
     _cd('Faraday constant'),
     symbol='F'
diff --git a/quantities/registry.py b/quantities/registry.py
@@ -27,6 +27,15 @@ def __getitem__(self, string):
 
         def __setitem__(self, string, val):
             assert isinstance(string, str)
+            try:
+                assert string not in self.__context
+            except AssertionError:
+                if val == self.__context[string]:
+                    return
+                raise KeyError(
+                    '%s has already been registered for %s' 
+                    % (string, self.__context[string])
+                )
             self.__context[string] = val
 
     __regex = re.compile(r'([A-Za-z])\.([A-Za-z])')
diff --git a/quantities/unitquantity.py b/quantities/unitquantity.py
@@ -378,6 +378,10 @@ class CompoundUnit(UnitQuantity):
     def __new__(cls, name):
         return UnitQuantity.__new__(cls, name, unit_registry[name])
 
+    def __init__(self, name):
+        # do not register
+        return
+
     @with_doc(UnitQuantity.__add__, use_header=False)
     def __repr__(self):
         return '1 %s'%self.name
diff --git a/quantities/units/acceleration.py b/quantities/units/acceleration.py
@@ -11,7 +11,7 @@
     standard_free_fall = gp = dynamic = geopotential = UnitQuantity(
     'standard_gravity',
     9.806650*m/s**2,
-    symbol='g',
+    symbol='g_0',
     u_symbol='g₀',
     doc='exact'
 )
diff --git a/quantities/units/angle.py b/quantities/units/angle.py
@@ -24,7 +24,7 @@
     mrad/1000,
     symbol='urad',
     u_symbol='µrad',
-    aliases=['milliradians']
+    aliases=['microradians']
 )
 
 turn = revolution = cycle = turns = circle = circles = UnitQuantity(
@@ -48,7 +48,7 @@
     symbol='arcmin',
     u_symbol='′',
     aliases=[
-        'arcmin', 'arcmins', 'arcminutes', 'arc_minute', 'arc_minutes',
+        'arcmins', 'arcminutes', 'arc_minute', 'arc_minutes',
         'angular_minute', 'angular_minutes'
     ]
 )
@@ -58,7 +58,7 @@
     symbol='arcsec',
     u_symbol='″',
     aliases=[
-        'arcsec', 'arcsecs', 'arcseconds', 'arc_second', 'arc_second',
+        'arcsecs', 'arcseconds', 'arc_second', 'arc_seconds',
         'angular_second', 'angular_seconds'
     ]
 )
diff --git a/quantities/units/area.py b/quantities/units/area.py
@@ -8,7 +8,6 @@
 are = ares = UnitQuantity(
     'are',
     100*m**2,
-    symbol='a',
     aliases=['ares']
 )
 b = barn = UnitQuantity(
@@ -38,7 +37,7 @@
     'hectare',
     10000*m**2,
     symbol='ha',
-    aliases=['hectare']
+    aliases=['hectares']
 )
 acre = international_acre = UnitQuantity(
     'acre',
diff --git a/quantities/units/electromagnetism.py b/quantities/units/electromagnetism.py
@@ -28,7 +28,7 @@
     mA/1000,
     symbol='uA',
     u_symbol='µA',
-    aliases=['uA', 'microamp', 'microamps', 'microamperes'])
+    aliases=['microamp', 'microamps', 'microamperes'])
 nA = nanoamp = nanoampere = UnitCurrent(
     'nanoampere',
     uA/1000,
@@ -155,8 +155,8 @@
 faraday = C12_faraday = UnitQuantity(
     'faraday',
     96485.3399*C,
-    symbol='F',
-    aliases=['faradays']
+    aliases=['faradays'],
+    doc='The symbol F is reserved for the farad'
 )
 gamma = UnitQuantity(
     'gamma',
@@ -189,7 +189,7 @@
     'stathenry',
     8.987554e11*H,
     symbol='stH',
-    aliases=['statH', 'stH']
+    aliases=['statH']
 )
 statmho = statS = stS = UnitQuantity(
     'statmho',
@@ -206,7 +206,7 @@
     'statvolt',
     2.997925e2*V,
     symbol='stV',
-    aliases=['statvolts', 'statV', 'stV']
+    aliases=['statvolts', 'statV']
 )
 unit_pole = UnitQuantity(
     'unit_pole',
@@ -215,7 +215,7 @@
 vacuum_permeability = mu_0 = magnetic_constant = UnitQuantity(
     'magnetic_constant',
     4*pi*10**-7*N/A**2,
-    symbol='epsilon_0',
+    symbol='mu_0',
     u_symbol='μ₀',
     aliases=['vacuum_permeability']
 )
diff --git a/quantities/units/force.py b/quantities/units/force.py
@@ -37,7 +37,7 @@
     'ounce_force',
     ounce*g_0,
     symbol='ozf',
-    aliases=['ozf']
+    aliases=['force_ounce']
 )
 lbf = force_pound = pound_force = UnitQuantity(
     'pound_force',
diff --git a/quantities/units/length.py b/quantities/units/length.py
@@ -34,7 +34,7 @@
     symbol='um',
     u_symbol='µm',
     aliases=[
-        'um', 'micron', 'microns', 'micrometers', 'micrometre', 'micrometres'
+        'micron', 'microns', 'micrometers', 'micrometre', 'micrometres'
     ]
 )
 nm = nanometer = nanometre = UnitLength(
@@ -52,7 +52,6 @@
 angstrom = UnitLength(
     'angstrom',
     nm/10,
-    symbol='A',
     u_symbol='Å',
     aliases=['angstroms']
 )
@@ -130,8 +129,9 @@
 pt = printers_point = point = UnitLength(
     'printers_point',
     127*mm/360,
-    symbol='pt',
-    aliases=['printers_points', 'point', 'points']
+    symbol='point',
+    aliases=['printers_points', 'points'],
+    doc='pt is reserved for pint'
 )
 pica = UnitLength(
     'pica',
diff --git a/quantities/units/mass.py b/quantities/units/mass.py
@@ -109,11 +109,19 @@
     u_symbol='℈',
     aliases=['scruples']
 )
+dr = dram = UnitMass(
+    'dram',
+    oz/16,
+    symbol='dr',
+    aliases=['drams'],
+    doc='avoirdupois dram'
+)
 drachm = apdram = UnitMass(
     'drachm',
     60*gr,
-    u_symbol='ʒ',
-    aliases=['dram', 'drams', 'drachms', 'apdrams']
+    u_symbol='  ',
+    aliases=['drachms', 'apdram', 'apdrams'],
+    doc='also known as the apothecary dram'
 )
 
 bag = UnitMass(
diff --git a/quantities/units/power.py b/quantities/units/power.py
@@ -31,7 +31,7 @@
 MW = megawatt = UnitQuantity(
     'megawatt',
     1000*kW,
-    symbol='mW',
+    symbol='MW',
     aliases=['megawatts']
 )
 hp = horsepower = UK_horsepower = British_horsepower = UnitQuantity(
diff --git a/quantities/units/pressure.py b/quantities/units/pressure.py
@@ -63,7 +63,7 @@
     'gigabar',
     1000*Mbar,
     symbol='Gbar',
-    aliases=['Gbar']
+    aliases=['gigabars']
 )
 atm = atmosphere = standard_atmosphere = UnitQuantity(
     'standard_atmosphere',
@@ -96,7 +96,7 @@
     0.1*N/m**2,
     symbol='Ba',
     aliases=[
-        'barie', 'baries', 'baryes', 'barad', 'barad', 'barrie', 'baryd',
+        'barie', 'baries', 'baryes', 'barad', 'barads', 'barrie', 'baryd',
         'baryed'
     ]
 )
@@ -105,7 +105,7 @@
     'millimeter_Hg',
     mm*mercury,
     symbol='mmHg',
-    aliases=['mmHg', 'millimeter_Hg'],
+    aliases=['mm_Hg', 'millimeter_Hg_0C'],
     doc="""
     The pressure exerted at the base of a column of fluid exactly 1 mm high,
     when the density of the fluid is exactly 13.5951 g/cm^3, at a place where
diff --git a/quantities/units/radiation.py b/quantities/units/radiation.py
@@ -42,7 +42,6 @@
 rads = UnitQuantity(
     'rads',
     1e-2*gray,
-    aliases=['rads'],
     doc='''
     rad is commonly used symbol for radian. 
     rads unit of radiation is deprecated.
diff --git a/quantities/units/temperature.py b/quantities/units/temperature.py
@@ -16,14 +16,14 @@
     K/1.8,
     symbol='degR',
     u_symbol='°R',
-    aliases=['degR', 'rankine']
+    aliases=['rankine']
 )
 degC = celsius = Celsius = UnitTemperature(
     'Celsius',
     K,
     symbol='degC',
     u_symbol='°C',
-    aliases=['degC', 'celsius'],
+    aliases=['celsius'],
     doc='''
     Unicode has special compatibility characters for ℃, but its use is
     discouraged by the unicode consortium.
@@ -34,7 +34,7 @@
     degR,
     symbol='degF',
     u_symbol='°F',
-    aliases=['degF', 'fahrenheit'],
+    aliases=['fahrenheit'],
     doc='''
     Unicode has special compatibility characters for ℉, but its use is
     discouraged by the unicode consortium.
diff --git a/quantities/units/time.py b/quantities/units/time.py
@@ -22,7 +22,7 @@
     ms/1000,
     symbol='us',
     u_symbol='µs',
-    aliases=['us', 'microseconds']
+    aliases=['microseconds']
 )
 ns = nanosecond = UnitTime(
     'nanosecond',
diff --git a/quantities/units/volume.py b/quantities/units/volume.py
@@ -34,7 +34,7 @@
     'gross_register_ton',
     100*foot**3,
     symbol='GRT',
-    aliases=['gross_register_ton', 'register_ton', 'register_tons']
+    aliases=['gross_register_tons', 'register_ton', 'register_tons']
 )
 
 acre_foot = UnitQuantity(
@@ -80,7 +80,9 @@
     'US_liquid_pint',
     US_liquid_quart/2,
     symbol='pt',
-    aliases=['pint', 'pints', 'liquid_pint', 'liquid_pints', 'US_liquid_pints']
+    aliases=[
+        'pint', 'pints', 'liquid_pint', 'liquid_pints', 'US_liquid_pints'
+    ],
 )
 cup = US_liquid_cup = UnitQuantity(
     'cup',
@@ -106,12 +108,12 @@
     36.36872*liter,
     doc='exact'
 )
-UK_liquid_gallon = Canadian_liquid_gallon = UK_liquid_gallon = UnitQuantity(
+UK_liquid_gallon = Canadian_liquid_gallon = UnitQuantity(
     'UK_liquid_gallon',
     4.54609*liter,
     aliases=[
         'UK_liquid_gallons', 'Canadian_liquid_gallon',
-        'Canadian_liquid_gallons', 'UK_liquid_gallon'
+        'Canadian_liquid_gallons'
     ],
     doc='exact'
 )
@@ -166,15 +168,11 @@
     aliases=['pecks']
 )
 
-fldr = UnitQuantity(
-    'fldr',
-    floz/8
-)
-dr = dram = UnitQuantity(
-    'dram',
-    floz/16,
-    symbol='dr',
-    aliases=['drams']
+fldr = fluid_dram = fluidram = UnitQuantity(
+    'fluid_dram',
+    floz/8,
+    symbol='fldr',
+    aliases=['fluid_drams', 'fluidram', 'fluidrams']
 )
 
 firkin = UnitQuantity(

Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,7 @@`
`17`	`17`	`_cd('elementary charge over h'),`
`18`	`18`	`symbol='e/h'`
`19`	`19`	`)`
`20`		`-F = Faraday_constant = UnitConstant(`
	`20`	`+Faraday_constant = UnitConstant(`
`21`	`21`	`'Faraday_constant',`
`22`	`22`	`_cd('Faraday constant'),`
`23`	`23`	`symbol='F'`
Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@`
`11`	`11`	`standard_free_fall = gp = dynamic = geopotential = UnitQuantity(`
`12`	`12`	`'standard_gravity',`
`13`	`13`	`9.806650m/s*2,`
`14`		`- symbol='g',`
	`14`	`+ symbol='g_0',`
`15`	`15`	`u_symbol='g₀',`
`16`	`16`	`doc='exact'`
`17`	`17`	`)`
Original file line number	Diff line number	Diff line change
`@@ -24,7 +24,7 @@`
`24`	`24`	`mrad/1000,`
`25`	`25`	`symbol='urad',`
`26`	`26`	`u_symbol='µrad',`
`27`		`- aliases=['milliradians']`
	`27`	`+ aliases=['microradians']`
`28`	`28`	`)`
`29`	`29`
`30`	`30`	`turn = revolution = cycle = turns = circle = circles = UnitQuantity(`
`@@ -48,7 +48,7 @@`
`48`	`48`	`symbol='arcmin',`
`49`	`49`	`u_symbol='′',`
`50`	`50`	`aliases=[`
`51`		`- 'arcmin', 'arcmins', 'arcminutes', 'arc_minute', 'arc_minutes',`
	`51`	`+ 'arcmins', 'arcminutes', 'arc_minute', 'arc_minutes',`
`52`	`52`	`'angular_minute', 'angular_minutes'`
`53`	`53`	`]`
`54`	`54`	`)`
`@@ -58,7 +58,7 @@`
`58`	`58`	`symbol='arcsec',`
`59`	`59`	`u_symbol='″',`
`60`	`60`	`aliases=[`
`61`		`- 'arcsec', 'arcsecs', 'arcseconds', 'arc_second', 'arc_second',`
	`61`	`+ 'arcsecs', 'arcseconds', 'arc_second', 'arc_seconds',`
`62`	`62`	`'angular_second', 'angular_seconds'`
`63`	`63`	`]`
`64`	`64`	`)`
Original file line number	Diff line number	Diff line change
`@@ -37,7 +37,7 @@`
`37`	`37`	`'ounce_force',`
`38`	`38`	`ounce*g_0,`
`39`	`39`	`symbol='ozf',`
`40`		`- aliases=['ozf']`
	`40`	`+ aliases=['force_ounce']`
`41`	`41`	`)`
`42`	`42`	`lbf = force_pound = pound_force = UnitQuantity(`
`43`	`43`	`'pound_force',`