Initial commit

dsmr_parser/parsers.py

@@ -0,0 +1,159 @@
+import logging
+import re
+
+from .objects import MBusObject, CosemObject
+from .exceptions import ParseError
+
+
+logger = logging.getLogger(__name__)
+
+
+class TelegramParser(object):
+
+    def __init__(self, telegram_specification):
+        """
+        :param telegram_specification: determines how the telegram is parsed
+        :type telegram_specification: dict
+        """
+        self.telegram_specification = telegram_specification
+
+    def _find_line_parser(self, line_value):
+
+        for obis_reference, parser in self.telegram_specification.items():
+            if re.search(obis_reference, line_value):
+                return obis_reference, parser
+
+        return None, None
+
+    def parse(self, line_values):
+        telegram = {}
+
+        for line_value in line_values:
+            obis_reference, dsmr_object = self.parse_line(line_value)
+
+            telegram[obis_reference] = dsmr_object
+
+        return telegram
+
+    def parse_line(self, line_value):
+        logger.debug('Parsing line\'%s\'', line_value)
+
+        obis_reference, parser = self._find_line_parser(line_value)
+
+        if not parser:
+            logger.warning("No line class found for: '%s'", line_value)
+            return None, None
+
+        return obis_reference, parser.parse(line_value)
+
+
+class DSMRObjectParser(object):
+
+    def __init__(self, *value_formats):
+        self.value_formats = value_formats
+
+    def _parse(self, line):
+        # Match value groups, but exclude the parentheses
+        pattern = re.compile(r'((?<=\()[0-9a-zA-Z\.\*]{0,}(?=\)))+')
+        values = re.findall(pattern, line)
+
+        # Convert empty value groups to None for clarity.
+        values = [None if value == '' else value for value in values]
+
+        if not values or len(values) != len(self.value_formats):
+            raise ParseError("Invalid '%s' line for '%s'", line, self)
+
+        return [self.value_formats[i].parse(value)
+                for i, value in enumerate(values)]
+
+
+class MBusParser(DSMRObjectParser):
+    """
+    Gas meter value parser.
+
+    These are lines with a timestamp and gas meter value.
+
+    Line format:
+    'ID (TST) (Mv1*U1)'
+
+     1   2     3   4
+
+    1) OBIS Reduced ID-code
+    2) Time Stamp (TST) of capture time of measurement value
+    3) Measurement value 1 (most recent entry of buffer attribute without unit)
+    4) Unit of measurement values (Unit of capture objects attribute)
+    """
+
+    def parse(self, line):
+        return MBusObject(self._parse(line))
+
+
+class CosemParser(DSMRObjectParser):
+    """
+    Cosem object parser.
+
+    These are data objects with a single value that optionally have a unit of
+    measurement.
+
+    Line format:
+    ID (Mv*U)
+
+    1  23  45
+
+    1) OBIS Reduced ID-code
+    2) Separator “(“, ASCII 28h
+    3) COSEM object attribute value
+    4) Unit of measurement values (Unit of capture objects attribute) – only if applicable
+    5) Separator “)”, ASCII 29h
+    """
+
+    def parse(self, line):
+        return CosemObject(self._parse(line))
+
+
+class ProfileGenericParser(DSMRObjectParser):
+    """
+    Power failure log parser.
+
+    These are data objects with multiple repeating groups of values.
+
+    Line format:
+    ID (z) (ID1) (TST) (Bv1*U1) (TST) (Bvz*Uz)
+
+    1   2   3     4     5   6    7     8   9
+
+    1) OBIS Reduced ID-code
+    2) Number of values z (max 10).
+    3) Identifications of buffer values (OBIS Reduced ID codes of capture objects attribute)
+    4) Time Stamp (TST) of power failure end time
+    5) Buffer value 1 (most recent entry of buffer attribute without unit)
+    6) Unit of buffer values (Unit of capture objects attribute)
+    7) Time Stamp (TST) of power failure end time
+    8) Buffer value 2 (oldest entry of buffer attribute without unit)
+    9) Unit of buffer values (Unit of capture objects attribute)
+    """
+
+    def parse(self, line):
+        raise NotImplementedError()
+
+
+class ValueParser(object):
+
+    def __init__(self, coerce_type):
+        self.coerce_type = coerce_type
+
+    def parse(self, value):
+
+        unit_of_measurement = None
+
+        if value and '*' in value:
+            value, unit_of_measurement = value.split('*')
+
+        # A value group is not required to have a value, and then coercing does
+        # not apply.
+        value = self.coerce_type(value) if value is not None else value
+
+        return {
+            'value': value,
+            'unit': unit_of_measurement
+        }