XML Reader for Construction Data

Overview

XML is used in construction for P6 schedules (XER), IFC-XML, COBie-XML, and buildingSMART Data Dictionary exports. This skill parses XML and converts to structured DataFrames.

Python Implementation

import xml.etree.ElementTree as ET
import pandas as pd
from typing import Dict, Any, List, Optional, Union
from dataclasses import dataclass
from pathlib import Path
import re


@dataclass
class XMLElement:
    """Parsed XML element."""
    tag: str
    attributes: Dict[str, str]
    text: Optional[str]
    children: List['XMLElement']


class ConstructionXMLReader:
    """Parse XML from construction systems."""

    def __init__(self):
        self.namespaces: Dict[str, str] = {}

    def parse_file(self, file_path: str) -> ET.Element:
        """Parse XML file and return root element."""
        tree = ET.parse(file_path)
        root = tree.getroot()

        # Extract namespaces
        self._extract_namespaces(root)

        return root

    def parse_string(self, xml_string: str) -> ET.Element:
        """Parse XML from string."""
        root = ET.fromstring(xml_string)
        self._extract_namespaces(root)
        return root

    def _extract_namespaces(self, root: ET.Element):
        """Extract namespace mappings."""
        # Find namespace declarations
        for attr, value in root.attrib.items():
            if attr.startswith('{'):
                ns = attr[1:attr.index('}')]
                self.namespaces[root.tag.split('}')[0][1:]] = ns

    def find_elements(self, root: ET.Element,
                      tag: str,
                      namespace: str = None) -> List[ET.Element]:
        """Find all elements with given tag."""
        if namespace:
            tag = f"{{{namespace}}}{tag}"
        return root.findall(f".//{tag}")

    def element_to_dict(self, element: ET.Element,
                        include_children: bool = True) -> Dict[str, Any]:
        """Convert element to dictionary."""
        result = {
            '_tag': element.tag.split('}')[-1] if '}' in element.tag else element.tag,
            '_text': element.text.strip() if element.text else None,
            **element.attrib
        }

        if include_children:
            for child in element:
                child_tag = child.tag.split('}')[-1] if '}' in child.tag else child.tag

                if child_tag in result:
                    # Multiple children with same tag - make list
                    if not isinstance(result[child_tag], list):
                        result[child_tag] = [result[child_tag]]
                    result[child_tag].append(self.element_to_dict(child))
                else:
                    result[child_tag] = self.element_to_dict(child)

        return result

    def elements_to_dataframe(self, elements: List[ET.Element]) -> pd.DataFrame:
        """Convert list of elements to DataFrame."""
        records = []
        for elem in elements:
            record = {'_tag': elem.tag.split('}')[-1]}
            record.update(elem.attrib)

            # Get direct text content
            if elem.text and elem.text.strip():
                record['_text'] = elem.text.strip()

            # Get child values
            for child in elem:
                child_tag = child.tag.split('}')[-1]
                if child.text and child.text.strip():
                    record[child_tag] = child.text.strip()
                # Also get child attributes
                for attr, val in child.attrib.items():
                    record[f"{child_tag}_{attr}"] = val

            records.append(record)

        return pd.DataFrame(records)

    def flatten_xml(self, root: ET.Element,
                    target_tag: str = None) -> pd.DataFrame:
        """Flatten XML to DataFrame."""
        if target_tag:
            elements = self.find_elements(root, target_tag)
        else:
            elements = list(root)

        return self.elements_to_dataframe(elements)


class P6XMLReader(ConstructionXMLReader):
    """Reader for Primavera P6 XML exports."""

    def parse_activities(self, root: ET.Element) -> pd.DataFrame:
        """Parse activities from P6 XML."""
        activities = self.find_elements(root, 'Activity')
        return self.elements_to_dataframe(activities)

    def parse_resources(self, root: ET.Element) -> pd.DataFrame:
        """Parse resources from P6 XML."""
        resources = self.find_elements(root, 'Resource')
        return self.elements_to_dataframe(resources)

    def parse_wbs(self, root: ET.Element) -> pd.DataFrame:
        """Parse WBS from P6 XML."""
        wbs = self.find_elements(root, 'WBS')
        return self.elements_to_dataframe(wbs)

    def parse_full_schedule(self, file_path: str) -> Dict[str, pd.DataFrame]:
        """Parse complete P6 schedule."""
        root = self.parse_file(file_path)
        return {
            'activities': self.parse_activities(root),
            'resources': self.parse_resources(root),
            'wbs': self.parse_wbs(root)
        }


class IFCXMLReader(ConstructionXMLReader):
    """Reader for IFC-XML files."""

    def parse_entities(self, root: ET.Element) -> pd.DataFrame:
        """Parse IFC entities."""
        # Find all Ifc* elements
        all_entities = []
        for elem in root.iter():
            if elem.tag.startswith('Ifc'):
                all_entities.append(elem)
        return self.elements_to_dataframe(all_entities)

    def get_entity_types(self, root: ET.Element) -> Dict[str, int]:
        """Count entity types."""
        counts = {}
        for elem in root.iter():
            tag = elem.tag
            if tag.startswith('Ifc'):
                counts[tag] = counts.get(tag, 0) + 1
        return counts


class COBieXMLReader(ConstructionXMLReader):
    """Reader for COBie XML files."""

    COBIE_SHEETS = ['Facility', 'Floor', 'Space', 'Zone', 'Type',
                    'Component', 'System', 'Assembly', 'Connection',
                    'Spare', 'Resource', 'Job', 'Document', 'Attribute']

    def parse_cobie(self, file_path: str) -> Dict[str, pd.DataFrame]:
        """Parse all COBie sheets."""
        root = self.parse_file(file_path)
        result = {}

        for sheet in self.COBIE_SHEETS:
            elements = self.find_elements(root, sheet)
            if elements:
                result[sheet] = self.elements_to_dataframe(elements)

        return result


class BSDDXMLReader(ConstructionXMLReader):
    """Reader for buildingSMART Data Dictionary exports."""

    def parse_classifications(self, root: ET.Element) -> pd.DataFrame:
        """Parse classification items."""
        items = self.find_elements(root, 'Classification')
        return self.elements_to_dataframe(items)

    def parse_properties(self, root: ET.Element) -> pd.DataFrame:
        """Parse property definitions."""
        props = self.find_elements(root, 'Property')
        return self.elements_to_dataframe(props)

Quick Start

reader = ConstructionXMLReader()

# Parse XML file
root = reader.parse_file("schedule.xml")

# Find specific elements
activities = reader.find_elements(root, "Activity")
print(f"Found {len(activities)} activities")

# Convert to DataFrame
df = reader.elements_to_dataframe(activities)

Common Use Cases

1. P6 Schedule Import

p6_reader = P6XMLReader()
schedule = p6_reader.parse_full_schedule("p6_export.xml")

activities = schedule['activities']
print(f"Activities: {len(activities)}")

2. COBie Data

cobie_reader = COBieXMLReader()
cobie_data = cobie_reader.parse_cobie("facility_cobie.xml")

components = cobie_data.get('Component', pd.DataFrame())

3. IFC-XML Analysis

ifc_reader = IFCXMLReader()
root = ifc_reader.parse_file("model.ifcxml")

# Count entity types
types = ifc_reader.get_entity_types(root)
for entity_type, count in sorted(types.items(), key=lambda x: -x[1])[:10]:
    print(f"{entity_type}: {count}")

Resources

• DDC Book: Chapter 2.1 - Semi-structured Data
• IFC-XML: buildingSMART specification