Python script for CSV to XML conversion

-- Python 2.7 - Desired CPython or Jython (due to improved thread support) -- Process must handle input files of an average of 50 thousand lines -- Output file must be validated against XSD as part of the process -- Process must manage logs to report problematic lines as well as generate CSV files with those lines -- Mapping between CSV columns and XML elements must be configurable Description of problem: The project consists of processing an input file (CSV format with variable columns) and transform it into an output file (XML following a specific XSD). More specifically, the problem is transforming a feed of products (CSV file) into Demandware's custom XML catalog format, while providing flexibility in the mapping of columns from the CSV into elements in the XML. Background: The input files contains records for products which need to be imported into the Demandware platform. Each record of the CSV represents a product, which can be simple or variant. Simple products are individual/independent products, while variant products are instances of a model (e.g. a Blue (color), Medium (waist) t-shirt) ++ Individual products are represented as "complete" <product> elements in the output XML, including child elements such as <images> or <custom-attributes>. ++ Variant products are represented in the CSV as records sharing the "item_group_id" column and are converted to the following in the XML: -- One <product> element that specifies the attributes that define the "model", including child elements such as <images> and <variations> E.g. <variation-attribute attribute-id="color"> or <variation-attribute attribute-id="size"> -- "partial" <product> elements in the output XML, including the <custom-attribute> values for each instance E.g. <custom-attribute attribute-id="color">GREENLEAF</custom-attribute> or <custom-attribute attribute-id="size">XS</custom-attribute> Attached are the files needed for the above examples and XSD.