def parse_query_expression()

in 5-app-infra/3-artifact-publish/docker/cdmc/tag_engine_api/DataCatalogController.py [0:0]

• 55 lines of code
• 15 McCabe index (conditional complexity)

    def parse_query_expression(self, uri, query_expression, column=None):
        
        query_str = None
        
        # analyze query expression
        from_index = query_expression.rfind(" from ", 0)
        where_index = query_expression.rfind(" where ", 0)
        project_index = query_expression.rfind("$project", 0)
        dataset_index = query_expression.rfind("$dataset", 0)
        table_index = query_expression.rfind("$table", 0)
        from_clause_table_index = query_expression.rfind(" from $table", 0)
        from_clause_backticks_table_index = query_expression.rfind(" from `$table`", 0)
        column_index = query_expression.rfind("$column", 0)
        
        #print('table_index: ', table_index)
        #print('column_index: ', column_index)
        
        if project_index != -1:
            project_end = uri.find('/') 
            project = uri[0:project_end]
            #print('project: ' + project)
            #print('project_index: ', project_index)
            
        if dataset_index != -1:
            dataset_start = uri.find('/datasets/') + 10
            dataset_string = uri[dataset_start:]
            dataset_end = dataset_string.find('/') 
            
            if dataset_end == -1:
                dataset = dataset_string[0:]
            else:
                dataset = dataset_string[0:dataset_end]
            print('dataset:', dataset)
            print('dataset_end:', dataset_end)
            print('dataset_index:', dataset_index)
        
        # $table referenced in from clause, use fully qualified table
        if from_clause_table_index > 0 or from_clause_backticks_table_index > 0:
             print('$table referenced in from clause')
             qualified_table = uri.replace('/project/', '.').replace('/datasets/', '.').replace('/tables/', '.')
             print('qualified_table:', qualified_table)
             print('query_expression:', query_expression)
             query_str = query_expression.replace('$table', qualified_table)
             print('query_str:', query_str)
             
        # $table is referenced somewhere in the expression, replace $table with actual table name
        else:
        
            if table_index != -1:
                #print('$table referenced somewhere, but not in the from clause')
                table_index = uri.rfind('/') + 1
                table_name = uri[table_index:]
                #print('table_name: ' + table_name)
                query_str = query_expression.replace('$table', table_name)
            
            # $project referenced in where clause too
            if project_index > -1:
                
                if query_str == None:
                    query_str = query_expression.replace('$project', project)
                else:
                    query_str = query_str.replace('$project', project)
                
                #print('query_str: ', query_str)
            
            # $dataset referenced in where clause too    
            if dataset_index > -1:

                if query_str == None:
                    query_str = query_expression.replace('$dataset', dataset)
                else:
                    query_str = query_str.replace('$dataset', dataset)
                    
                print('query_str: ', query_str)
            
        # table not in query expression (e.g. select 'string')
        if table_index == -1 and query_str == None:
            query_str = query_expression
            
        if column_index != -1:
            
            if query_str == None:
                query_str = query_expression.replace('$column', column)
            else:
                query_str = query_str.replace('$column', column)
        
        #print('returning query_str:', query_str)            
        return query_str