CWICR Data Loader
Business Case
Problem Statement
DDC CWICR database is distributed in multiple formats:
- Apache Parquet (optimized for analytics)
- Excel workbooks (human-readable)
- CSV files (universal exchange)
- Qdrant snapshots (vector search)
Applications need unified data access regardless of source format.
Solution
Universal data loader supporting all CWICR formats with automatic schema detection, validation, and pandas DataFrame conversion.
Business Value
- Format agnostic - Load from any CWICR distribution
- Validated data - Automatic schema validation
- Memory efficient - Lazy loading for large datasets
- Type-safe - Proper data types preserved
Technical Implementation
Prerequisites
pip install pandas pyarrow openpyxl qdrant-clientPython Implementation
import pandas as pd
import pyarrow.parquet as pq
from pathlib import Path
from typing import Optional, Dict, Any, List, Union
from dataclasses import dataclass, field
from enum import Enum
import json
class CWICRFormat(Enum):
"""Supported CWICR data formats."""
PARQUET = "parquet"
EXCEL = "excel"
CSV = "csv"
QDRANT = "qdrant"
JSON = "json"
class CWICRLanguage(Enum):
"""Supported languages in CWICR database."""
ARABIC = "ar"
CHINESE = "zh"
GERMAN = "de"
ENGLISH = "en"
SPANISH = "es"
FRENCH = "fr"
HINDI = "hi"
PORTUGUESE = "pt"
RUSSIAN = "ru"
@dataclass
class CWICRSchema:
"""CWICR database schema definition."""
# Core fields
work_item_code: str = "work_item_code"
description: str = "description"
unit: str = "unit"
category: str = "category"
# Cost fields
unit_price: str = "unit_price"
labor_cost: str = "labor_cost"
material_cost: str = "material_cost"
equipment_cost: str = "equipment_cost"
overhead_cost: str = "overhead_cost"
# Norm fields
labor_norm: str = "labor_norm"
material_norm: str = "material_norm"
equipment_norm: str = "equipment_norm"
# Metadata
language: str = "language"
region: str = "region"
currency: str = "currency"
last_updated: str = "last_updated"
# Optional embedding
embedding: str = "embedding"
@dataclass
class CWICRWorkItem:
"""Represents a single work item from CWICR database."""
work_item_code: str
description: str
unit: str
category: str
unit_price: float = 0.0
labor_cost: float = 0.0
material_cost: float = 0.0
equipment_cost: float = 0.0
overhead_cost: float = 0.0
labor_norm: float = 0.0
labor_unit: str = "h"
resources: List[Dict[str, Any]] = field(default_factory=list)
language: str = "en"
region: str = ""
currency: str = "USD"
@dataclass
class CWICRResource:
"""Represents a resource (material, labor, equipment)."""
resource_code: str
description: str
unit: str
unit_price: float
resource_type: str # 'labor', 'material', 'equipment'
category: str = ""
class CWICRDataLoader:
"""Universal loader for CWICR database formats."""
REQUIRED_COLUMNS = ['work_item_code', 'description', 'unit']
NUMERIC_COLUMNS = ['unit_price', 'labor_cost', 'material_cost',
'equipment_cost', 'labor_norm']
def __init__(self):
self.schema = CWICRSchema()
self._cache: Dict[str, pd.DataFrame] = {}
def load(self, source: str,
format: Optional[CWICRFormat] = None,
language: Optional[CWICRLanguage] = None,
use_cache: bool = True) -> pd.DataFrame:
"""Load CWICR data from any supported source."""
cache_key = f"{source}_{language}"
if use_cache and cache_key in self._cache:
return self._cache[cache_key]
# Auto-detect format if not specified
if format is None:
format = self._detect_format(source)
# Load based on format
if format == CWICRFormat.PARQUET:
df = self._load_parquet(source)
elif format == CWICRFormat.EXCEL:
df = self._load_excel(source)
elif format == CWICRFormat.CSV:
df = self._load_csv(source)
elif format == CWICRFormat.JSON:
df = self._load_json(source)
else:
raise ValueError(f"Unsupported format: {format}")
# Validate and normalize
df = self._validate_schema(df)
df = self._normalize_types(df)
# Filter by language if specified
if language and 'language' in df.columns:
df = df[df['language'] == language.value]
# Cache result
if use_cache:
self._cache[cache_key] = df
return df
def _detect_format(self, source: str) -> CWICRFormat:
"""Auto-detect data format from source."""
path = Path(source)
if path.suffix.lower() == '.parquet':
return CWICRFormat.PARQUET
elif path.suffix.lower() in ['.xlsx', '.xls']:
return CWICRFormat.EXCEL
elif path.suffix.lower() == '.csv':
return CWICRFormat.CSV
elif path.suffix.lower() == '.json':
return CWICRFormat.JSON
else:
raise ValueError(f"Cannot detect format: {source}")
def _load_parquet(self, source: str) -> pd.DataFrame:
"""Load from Parquet file."""
return pd.read_parquet(source)
def _load_excel(self, source: str,
sheet_name: str = "WorkItems") -> pd.DataFrame:
"""Load from Excel workbook."""
try:
return pd.read_excel(source, sheet_name=sheet_name)
except:
# Try first sheet if named sheet doesn't exist
return pd.read_excel(source, sheet_name=0)
def _load_csv(self, source: str) -> pd.DataFrame:
"""Load from CSV file."""
# Try different encodings
for encoding in ['utf-8', 'latin-1', 'cp1252']:
try:
return pd.read_csv(source, encoding=encoding)
except UnicodeDecodeError:
continue
raise ValueError(f"Cannot read CSV with any encoding: {source}")
def _load_json(self, source: str) -> pd.DataFrame:
"""Load from JSON file."""
with open(source, 'r', encoding='utf-8') as f:
data = json.load(f)
if isinstance(data, list):
return pd.DataFrame(data)
elif isinstance(data, dict) and 'items' in data:
return pd.DataFrame(data['items'])
else:
return pd.DataFrame([data])
def _validate_schema(self, df: pd.DataFrame) -> pd.DataFrame:
"""Validate DataFrame against CWICR schema."""
# Check required columns
missing = set(self.REQUIRED_COLUMNS) - set(df.columns)
if missing:
raise ValueError(f"Missing required columns: {missing}")
return df
def _normalize_types(self, df: pd.DataFrame) -> pd.DataFrame:
"""Normalize column types."""
for col in self.NUMERIC_COLUMNS:
if col in df.columns:
df[col] = pd.to_numeric(df[col], errors='coerce').fillna(0)
# Ensure string columns
for col in ['work_item_code', 'description', 'unit', 'category']:
if col in df.columns:
df[col] = df[col].astype(str)
return df
def load_resources(self, source: str,
format: Optional[CWICRFormat] = None) -> pd.DataFrame:
"""Load resources separately."""
if format is None:
format = self._detect_format(source)
if format == CWICRFormat.EXCEL:
try:
return pd.read_excel(source, sheet_name="Resources")
except:
return pd.DataFrame()
else:
return self.load(source, format)
def get_work_item(self, df: pd.DataFrame,
code: str) -> Optional[CWICRWorkItem]:
"""Get single work item by code."""