Introducing the exposurelib for the elementary Spatialite database class

exposurejapan/database.py

@@ -17,7 +17,7 @@
 # along with this program. If not, see http://www.gnu.org/licenses/.
 
 import logging
-import sqlite3
+from exposurelib.database import SpatialiteDatabase
 import pandas
 
 
@@ -25,57 +25,7 @@ import pandas
 logger = logging.getLogger(__name__)
 
 
-class Database:
-    """The Database class represents a Spatialite database. It manages the database
-    connection and cursor. Upon connection, the Spatialite extension is loaded.
-
-    Args:
-        database_filepath (str):
-            File path for the Spatialite database file.
-        spatialite_filepath (str):
-            File path of the Spatialite extension.
-
-    Attributes:
-        database_filepath (str): Spatialite database file path.
-        spatialite_filepath (str): File path to the Spatialite extension.
-    """
-
-    def __init__(self, database_filepath, spatialite_filepath="mod_spatialite"):
-        self.database_filepath = database_filepath
-        self.spatialite_filepath = spatialite_filepath
-
-        self.connection = None
-        self.cursor = None
-
-    def create_connection_and_cursor(self, init_spatial_metadata=True):
-        """Create a database connection, loads the Spatialite extension and initializes it.
-
-        Attributes:
-            init_spatial_metadata (bool, optional):
-                If set, the InitSpatialMetadata function of Spatialite is invoked
-        """
-
-        # Create SQLite database for the exposure data
-        logger.debug("Connecting to database at %s" % self.database_filepath)
-        self.connection = sqlite3.connect(self.database_filepath)
-        logger.debug("Connection to database established")
-
-        self.connection.enable_load_extension(True)
-        sql_statement = "SELECT load_extension('%s');" % self.spatialite_filepath
-        self.connection.execute(sql_statement)
-        if init_spatial_metadata:
-            self.connection.execute("SELECT InitSpatialMetaData(1);")
-            logger.debug("Spatialite extension loaded and initialized")
-
-        versions = self.connection.execute("SELECT sqlite_version(), spatialite_version()")
-        for row in versions:
-            logger.debug("SQLite version: %s" % row[0])
-            logger.debug("Spatialite version: %s" % row[1])
-
-        self.cursor = self.connection.cursor()
-
-
-class JapanDatabase(Database):
+class JapanDatabase(SpatialiteDatabase):
     """The JapanDatabase class represents a Spatialite database for the Japan
     exposure model. It is derived from the generic Database class.
 
@@ -91,12 +41,17 @@ class JapanDatabase(Database):
     """
 
     def __init__(self, database_filepath, spatialite_filepath="mod_spatialite"):
-        Database.__init__(self, database_filepath, spatialite_filepath)
+        SpatialiteDatabase.__init__(self, database_filepath, spatialite_filepath)
 
     def create_tables(self):
         """
         Creates all necessary tables in the database. These are:
-            District : Stores the districts with their IDs, names and geometries
+            District: Stores the districts with their IDs, names and geometries
+            DwellingNumber: Stores the number of dwellings depending on building types,
+                construction material and number of stories for each district
+            BuildingType: Stores the different types of buildings
+            ConstructionMaterial: Stores the construction-material types
+            NumberStories: Stores the classifications of numbers of stories
         """
 
         # Create table District
@@ -252,8 +207,8 @@ class JapanDatabase(Database):
                 File path to the boundary file
         """
 
-        boundary_db = Database(district_boundary_filepath, self.spatialite_filepath)
-        boundary_db.create_connection_and_cursor()
+        boundary_db = SpatialiteDatabase(district_boundary_filepath, self.spatialite_filepath)
+        boundary_db.connect(init_spatial_metadata=False)
 
         sql_statement = "SELECT key_code_ward, "
         sql_statement += "CITY_NAME, "

exposurejapan/exposurejapan.py

@@ -20,7 +20,7 @@
 import logging
 import sys
 import sqlite3
-from database import JapanDatabase  # pylint: disable=E0611,E0401
+from .database import JapanDatabase  # pylint: disable=E0611,E0401
 
 
 # Add a logger printing error, warning, info and debug messages to the screen
@@ -37,13 +37,13 @@ def main():
     db = JapanDatabase("test.sqlite", "/usr/lib64/mod_spatialite.so.7")
 
     try:
-        db.create_connection_and_cursor()
+        db.connect()
     except sqlite3.OperationalError:
         logger.warning("Spatialite extension cannot be loaded. Exiting ...")
         exit()
     db.create_tables()
-    db.read_districts_and_boundaries("../data/estat_bound_municipal.gpkg")
-    db.import_exposure_data("../data/e008_3e.xlsx")
+    db.read_districts_and_boundaries("data/estat_bound_municipal.gpkg")
+    db.import_exposure_data("data/e008_3e.xlsx")
 
     # Leave the program
     sys.exit()

setup.py

@@ -29,7 +29,10 @@ setup(
     keywords="exposuremodel, building",
     author="Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ",
     license="AGPLv3+",
-    install_requires=["pandas", "numpy", "scipy"],
+    install_requires=[
+        "pandas",
+        "exposurelib@https://git.gfz-potsdam.de/dynamicexposure/globaldynamicexposure/exposure-lib/-/archive/master/exposure-lib-master.zip",  # noqa: E501
+    ],
     extras_require={"tests": tests_require, "linters": linters_require},
     packages=find_packages(),
     entry_points={"console_scripts": ["exposurejapan = exposurejapan.exposurejapan:main"]},