Source code for mdf_reader.data_models.schemas

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""

This module has functions to manage data model
schema files and objects according to the
requirements of the data reader tool

"""

import os
import sys
import json
import logging
import shutil
from copy import deepcopy
import glob

from .. import properties

if sys.version_info[0] >= 3:
[docs] py3 = True
else: py3 = False
[docs]toolPath = os.path.dirname(os.path.abspath(__file__))
[docs]schema_lib = os.path.join(toolPath,'lib')
[docs]templates_path = os.path.join(schema_lib,'templates','schemas')
[docs]def read_schema(schema_name = None, ext_schema_path = None): """ Reads a data model schema file to a dictionary and completes it by adding explicitly information the reader tool needs Keyword Arguments ----------------- schema_name : str, optional The name of data model to read. This is for data models included in the tool ext_schema_path : str, optional The path to the external data model schema file Either schema_name or ext_schema_path must be provided. Returns ------- dict Data model schema """ # 1. Validate input if schema_name: if schema_name not in properties.supported_data_models: print('ERROR: \n\tInput data model "{}" not supported. See mdf_reader.properties.supported_data_models for supported data models'.format(schema_name)) return else: schema_path = os.path.join(schema_lib,schema_name) else: schema_path = os.path.abspath(ext_schema_path) schema_name = os.path.basename(schema_path) schema_file = os.path.join(schema_path, schema_name + '.json') if not os.path.isfile(schema_file): logging.error('Can\'t find input schema file {}'.format(schema_file)) return # 2. Get schema with open(schema_file) as fileObj: schema = json.load(fileObj) # 3. Expand schema # Fill in the initial schema to "full complexity": to homogeneize schema, # explicitly add info that is implicit to given situations/data models # One report per record: make sure later changes are reflected in MULTIPLE # REPORTS PER RECORD case below if we ever use it! # Currently only supported case: one report per record (line) # 3.1. First check for no header case: sequential sections if not schema['header']: if not schema['sections']: logging.error('\'sections\' block needs to be defined in a schema with no header. Error in data model schema file {}'.format(schema_file)) return schema['header'] = dict() if not schema['header'].get('multiple_reports_per_line'): # 3.2. Make no section formats be internally treated as 1 section format if not schema.get('sections'): if not schema.get('elements'): logging.error('Data elements not defined in data model schema file {} under key \'elements\' '.format(schema_file)) return schema['sections'] = {properties.dummy_level:{'header':{},'elements':schema.get('elements')}} schema['header']['parsing_order'] = [{'s':[properties.dummy_level]}] schema.pop('elements',None) schema['sections'][properties.dummy_level]['header']['delimiter'] = schema['header'].get('delimiter') schema['header'].pop('delimiter',None) schema['sections'][properties.dummy_level]['header']['field_layout'] = schema['header'].get('field_layout') schema['header'].pop('field_layout',None) # 3.3. Make parsing order explicit if not schema['header'].get('parsing_order'):# assume sequential schema['header']['parsing_order'] = [{'s':list(schema['sections'].keys())}] # 3.4. Make disable_read and field_layout explicit: this is ruled by delimiter being set, # unless explicitly set for section in schema['sections'].keys(): if schema['sections'][section]['header'].get('disable_read'): continue else: schema['sections'][section]['header']['disable_read'] = False if not schema['sections'][section]['header'].get('field_layout'): delimiter = schema['sections'][section]['header'].get('delimiter') schema['sections'][section]['header']['field_layout'] = 'delimited' if delimiter else 'fixed_width' for element in schema['sections'][section]['elements'].keys(): if schema['sections'][section]['elements'][element].get('column_type') in properties.numpy_integers: np_integer = schema['sections'][section]['elements'][element].get('column_type') pd_integer = properties.pandas_nan_integers.get(np_integer) schema['sections'][section]['elements'][element].update({'column_type':pd_integer}) return schema else: logging.error('Multile reports per line data model: not yet supported') return
# 1X: MULTIPLE REPORTS PER RECORD # !!!! NEED TO ADD SECTION LENS TO THE REPORT'S SECTION'S HEADER!!! # CAN INFER FROM ELEMENTS LENGHT AND ADD, OR MAKE AS REQUIREMENT TO BE GIVEN # global name_report_section # Have to assess how the section splitting works when x sequential # sections are declared, and only x-y are met. #if not schema['header'].get('reports_per_line'): # schema['header']['reports_per_line'] = 24 #if not schema.get('sections'): # schema['sections'] = dict() # schema['header']['parsing_order'] = [{'s':[]}] # for i in range(1,schema['header']['reports_per_line'] + 1): # schema['sections'].update({str(i):{'header':{},'elements':deepcopy(schema.get('elements'))}}) #else: # name_report_section = list(schema['sections'].keys())[-1] # schema['header']['name_report_section'] == name_report_section # schema['header']['parsing_order'] = [{'s':list(schema['sections'].keys())[:-1]}] # for i in range(1,schema['header']['reports_per_line'] + 1): # schema['sections'].update({str(i):schema['sections'].get(name_report_section)}) # schema['sections'].pop(name_report_section,None) #for i in range(1,schema['header']['reports_per_line'] + 1): # schema['header']['parsing_order'][0]['s'].append(str(i)) #return schema
[docs]def df_schema(df_columns, schema): """ Creates a simple attribute dictionary for the elements in a dataframe from its data model schema Parameters ---------- df_columns : list The columns in the data frame (data elements from the data model) schema : dict The data model schema Returns ------- dict Data elements attributes """ def clean_schema(columns,schema): # Could optionally add cleaning of element descriptors that only apply # to the initial reading of the data model: field_length, etc.... for element in list(schema): if element not in columns: schema.pop(element) return flat_schema = dict() # Flatten main model schema for section in schema.get('sections'): if section == properties.dummy_level: flat_schema.update(schema['sections'].get(section).get('elements')) elif schema['sections'].get(section).get('header').get('disable_read'): flat_schema.update( { (section, section): {'column_type':'object'} }) else: flat_schema.update( { (section, x): schema['sections'].get(section).get('elements').get(x) for x in schema['sections'].get(section).get('elements') }) clean_schema(df_columns, flat_schema) return flat_schema
[docs]def templates(): """ Lists the name of the available schema file templates Returns ------- list Schema file templates alias """ schemas = glob.glob(os.path.join(templates_path,'*.json')) return [ os.path.basename(x).split(".")[0] for x in schemas ]
[docs]def copy_template(schema, out_dir = None,out_path = None): """ Copies a schema file template to an output file or path Parameters ---------- schema : str Schema template name to copy Keyword Arguments ----------------- out_dir : dict, opt Directory to copy schema file template to out_path : dict, opt Full filename to copy schema file template to Either out_dir or out_path must be provided """ schemas = templates() if schema in schemas: schema_path = os.path.join(templates_path,schema + '.json') schema_out = out_path if out_path else os.path.join(out_dir,schema + '.json') shutil.copyfile(schema_path, schema_out) if os.path.isfile( schema_out): print('Schema template {0} copied to {1}'.format(schema, schema_out)) return else: print('copy_template ERROR:') print('\tError copying schema template {0} copied to {1}'.format(schema, schema_out)) return else: print('copy_template ERROR:') print('\tRequested template {} must be a valid name.'.format(schema)) print('\tValid names are: {}'.format(", ".join(schemas))) return