Various minor updates, basic Schedule class. Added a SixData class to manage conversions of YYMMDD to/from more pythonic objects.

src/national_rail_timetable/mca_queries.py

@@ -8,11 +8,13 @@ It seems unlikely that the CIF format will be modified any time soon.
 """
 
 # Imports
-from dataclasses import dataclass, field
 import sqlite3
+from datetime import datetime
+from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any
 
+import numpy as np
 import pandas as pd
 from sqlalchemy import (
     Column,
@@ -24,11 +26,55 @@ from sqlalchemy import (
     select,
 )
 
+from national_rail_timetable.mca_record_types import (
+    BS,
+    BX,
+    CR,
+    LI,
+    LO,
+    LT,
+    BaseRecord,
+)
 from national_rail_timetable.parsing import validate_db_path
-from national_rail_timetable.mca_record_types import LI
 
 
 # Classes
+class SixDate(str):
+    def __post_init__(self):
+        assert len(self) == 6
+        assert self.isnumeric()
+
+    def as_unix(self):
+        return f"20{self[:2]}-{self[2:4]}-{self[-2:]}"
+
+    def as_numpy(self):
+        return np.datetime64(self.as_unix())
+
+    def as_datetime(self):
+        return datetime.fromisoformat(self.as_unix())
+
+    @classmethod
+    def from_unix(cls, unix_str: str):
+        return cls(unix_str[2:].replace("-", "").replace("/", ""))
+
+    @classmethod
+    def from_numpy(cls, np_dt: np.datetime64):
+        return cls.from_unix(str(np_dt).split("T")[0])
+
+    @classmethod
+    def from_datetime(cls, dt: datetime):
+        return cls.from_unix(str(dt).split(" ")[0])
+
+
+@dataclass
+class Schedule:
+    sn: int
+    bs: pd.Series
+    bx: pd.Series
+    loit: pd.DataFrame
+    cr: pd.DataFrame
+
+
 @dataclass
 class Timetable:
     engine: Engine = field(
@@ -76,7 +122,7 @@ class Timetable:
             + "# Result of mca_queries.py's Timetable._hardcode_table_dataclasses. \n"
             + "\n"
             + "# Imports \n"
-            + "from dataclasses import dataclass \n"
+            + "from dataclasses import dataclass, field \n"
             + "from typing import Any \n"
             + "from sqlalchemy import Column, MetaData, Table, String, Integer \n"
             + "\n"
@@ -84,6 +130,13 @@ class Timetable:
             + "metadata = MetaData() \n"
             + "\n"
             + "# Classes \n"
+            + "@dataclass \n"
+            + "class BaseRecord: \n"
+            + "\tall: Table \n\n"
+            + "\t@property \n"
+            + "\tdef schedule_number(self) -> Column[Integer]: ... \n\n"
+            + "\t@property \n"
+            + "\tdef line_number(self) -> Column[Integer]: ... \n\n"
         )
         for name in self.tables:
             columns = [column.name for column in self.tables[name].columns]
@@ -96,7 +149,7 @@ class Timetable:
             )
             text += (
                 "@dataclass \n"
-                + f"class _{rr}_base: \n"
+                + f"class _{rr}_base(BaseRecord): \n"
                 + "\tall: Table \n\n"
                 + "".join(
                     [
@@ -128,10 +181,36 @@ class Timetable:
         with self.engine.connect() as connection:
             return pd.read_sql(query, connection)
 
+    def _fetch_record_of_schedule(
+        self,
+        schedule_number: int,
+        record_type: BaseRecord,
+    ) -> pd.DataFrame:
+        return self.execute(
+            select(record_type.all).where(
+                record_type.schedule_number == schedule_number
+            )
+        )
+
+    def fetch_schedule(self, schedule_number: int) -> Schedule:
+        return Schedule(
+            sn=schedule_number,
+            bs=self._fetch_record_of_schedule(schedule_number, BS).iloc[0],
+            bx=self._fetch_record_of_schedule(schedule_number, BX).iloc[0],
+            loit=pd.concat(
+                [
+                    self._fetch_record_of_schedule(schedule_number, LO),
+                    self._fetch_record_of_schedule(schedule_number, LI),
+                    self._fetch_record_of_schedule(schedule_number, LT),
+                ]
+            ).reset_index(drop=True),
+            cr=self._fetch_record_of_schedule(schedule_number, CR),
+        )
+
 
 # Script
 def main():
-    print(Timetable().execute(select(LI.all).where(LI.schedule_number == 10)))
+    print(Timetable().fetch_schedule(30))
     return None
 
 

src/national_rail_timetable/mca_record_types.py

@@ -5,7 +5,7 @@
 # Result of mca_queries.py's Timetable._hardcode_table_dataclasses. 
 
 # Imports 
-from dataclasses import dataclass 
+from dataclasses import dataclass, field 
 from typing import Any 
 from sqlalchemy import Column, MetaData, Table, String, Integer 
 
@@ -13,6 +13,16 @@ from sqlalchemy import Column, MetaData, Table, String, Integer
 metadata = MetaData() 
 
 # Classes 
+@dataclass 
+class BaseRecord: 
+    all: Table 
+
+    @property 
+    def schedule_number(self) -> Column[Integer]: ... 
+
+    @property 
+    def line_number(self) -> Column[Integer]: ... 
+
 _BS_columns = Table( 
     'raw_mca_bs', 
     metadata, 
@@ -47,7 +57,7 @@ _BS_columns = Table(
 ) 
 
 @dataclass 
-class _BS_base: 
+class _BS_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -183,7 +193,7 @@ _HD_columns = Table(
 ) 
 
 @dataclass 
-class _HD_base: 
+class _HD_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -250,7 +260,7 @@ _ZZ_columns = Table(
 ) 
 
 @dataclass 
-class _ZZ_base: 
+class _ZZ_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -291,7 +301,7 @@ _TA_columns = Table(
 ) 
 
 @dataclass 
-class _TA_base: 
+class _TA_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -382,7 +392,7 @@ _CR_columns = Table(
 ) 
 
 @dataclass 
-class _CR_base: 
+class _CR_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -499,7 +509,7 @@ _LT_columns = Table(
 ) 
 
 @dataclass 
-class _LT_base: 
+class _LT_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -567,7 +577,7 @@ _LI_columns = Table(
 ) 
 
 @dataclass 
-class _LI_base: 
+class _LI_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -651,7 +661,7 @@ _TD_columns = Table(
 ) 
 
 @dataclass 
-class _TD_base: 
+class _TD_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -700,7 +710,7 @@ _AA_columns = Table(
 ) 
 
 @dataclass 
-class _AA_base: 
+class _AA_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -796,7 +806,7 @@ _LO_columns = Table(
 ) 
 
 @dataclass 
-class _LO_base: 
+class _LO_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -869,7 +879,7 @@ _BX_columns = Table(
 ) 
 
 @dataclass 
-class _BX_base: 
+class _BX_base(BaseRecord): 
     all: Table 
 
     @property 
@@ -933,7 +943,7 @@ _TI_columns = Table(
 ) 
 
 @dataclass 
-class _TI_base: 
+class _TI_base(BaseRecord): 
     all: Table 
 
     @property