Make representation string for vehicle plate

biensoxe/core.py

@@ -14,6 +14,8 @@
 from pydantic import constr
 from pydantic.dataclasses import dataclass
 
+from .utils import split_to_triples
+
 
 # Use this regex to strip out all illegal characters
 REGEX_CLEAN_PLATE_NUMBER = re.compile(r'[^a-zđA-ZĐ0-9]')
@@ -38,8 +40,8 @@ class NonBusinessSpecialSeries(enum.Enum):
     R = 'R'   # 51R-14139
 
 
+    # This plate has yellow background
 class SpecialEconomicZoneSeries(enum.Enum):
-    ''' This plate has yellow background '''
     LB = 'LB'  # Lao Bảo
     CT = 'CT'  # Cầu Treo
     LA = 'LA'  # Don't know where it is
@@ -130,32 +132,49 @@ class VehicleType(enum.IntEnum):
 
 @dataclass
 class VietnamVehiclePlate:
-    '''Class to represent a Vietnamese vehicle number plate.
+    """Class to represent a Vietnamese vehicle number plate.
 
     Library user must not create instance directly from this class constructer.
-    Please call :function:`VietnamVehiclePlate.from_string` instead.
+    Please call :meth:`VietnamVehiclePlate.from_string` instead.
 
     :param compact: Compact string of plate number, where all characters other than letters and numbers are stripped.
     :param vehicle_type: Type of vehicle (of :class:`VehicleType` type), deduced from the plate number.
     :param series: Series string of the plate number.
     :param order: Registration order number.
     :param locality: Locality where this vehicle was registered.
     :param dip_country: Foreign country where the vehicle owner came from (in case of diplomat, foreigner use).
-    '''
+    """
+
     compact: constr(regex=f'[a-zA-Z0-9]+')
     vehicle_type: VehicleType
     series: str
     order: str
     locality: Optional[str] = None
     dip_country: Optional[str] = None
 
+    def __str__(self):
+        """Return string representation of this object."""
+        vehicle_type = self.vehicle_type
+        mototcycle_types = (VehicleType.DOMESTIC_MOTORCYCLE_UNDER_50CC, VehicleType.DOMESTIC_MOTORCYCLE_OVER_175CC,
+                            VehicleType.DOMESTIC_MOTORCYCLE_50_TO_175CC)
+        if len(self.order) <= 4:
+            order = self.order
+        else:
+            # For number plate since 2010, the order will be separated with dot,
+            # to be easier to read.
+            order = '.'.join(split_to_triples(self.order))
+        if vehicle_type in mototcycle_types:
+            return f'{self.locality}-{self.series} {order}'
+        return f'{self.locality}{self.series}-{order}'
+
     @classmethod
     def from_string(cls, number_sequence: str):
-        '''Parse the number string of Vietnamese vehicle registration plate.
+        """Parse the number string of Vietnamese vehicle registration plate.
+
         :param number_sequence: Number string as printed on the plate.
         :return: :class:`VietnamVehiclePlate` object.
         :raises ValueError: If the number string could not be parsed.
-        '''
+        """
         compact = REGEX_CLEAN_PLATE_NUMBER.sub('', number_sequence.upper())
         if not compact:
             raise ValueError('Empty string')

biensoxe/utils.py

@@ -0,0 +1,6 @@
+def split_to_triples(string: str):
+    """Split a string to many substrings of 3-character.
+
+    For example, split "abcdef" to "abc", "def".
+    """
+    return tuple(string[i: i + 3] for i in range(0, len(string), 3))

tests/test_biensoxe.py

@@ -71,3 +71,8 @@ def test_high_capacity_motorcycle(original_string, locality, series):
     assert plate.vehicle_type == VehicleType.DOMESTIC_MOTORCYCLE_OVER_175CC
     assert plate.locality == locality
     assert plate.series == series
+
+
+def test_invalid_plate_number():
+    with pytest.raises(ValueError):
+        VietnamVehiclePlate.from_string('XXYYZZ11')