Skip to main content

Map flat data to structured JSON via a mapping.

Project description

# jsonmapping [![Build Status](https://travis-ci.org/pudo/jsonmapping.svg?branch=master)](https://travis-ci.org/pudo/jsonmapping)

To transform flat data structures into nested object graphs matching JSON
schema definitions, this package defines a mapping language. It defines how
the columns of a source data set (e.g. a CSV file, database table) are to be
converted to the fields of a JSON schema.

The format allows mapping nested structures, including arrays. It also supports
the application of very basic data transformation steps, such as generating a
URL slug or hashing a column value.

## Example mapping

The mapping format is independent of any particular JSON schema, such that
multiple mappings could be defined for any one particular schema.

```json
{
"schema": {"$ref": "http://www.popoloproject.com/schemas/person.json"},
"mapping": {
"id": {"column": "person_id"},
"name": {"column": "person_name"},
"memberships": [{
"mapping": {
"role": {"default": "Member of Organization"},
"organization": {
"mapping": {
"id": {
"columns": ["org_id"],
"constant": "default-org"
},
"name": {
"column": "org_name",
"constant": "Default Organization",
"transforms": ["strip"]
}
}
}
}
}]
}
}
```

This mapping would apply to a four-column CSV file and map it to a set of
nested JSON objects (a [Popolo](http://www.popoloproject.com/) person, with a
membership in an organization).

## Data Transforms

While ``jsonmapper`` is not a data cleaning tool, it supports some very basic
data transformation operations that can be applied on a particular column or
set of columns. These include:

* ``coalesce``: Select the first non-null value from the list of items.
* ``slugify``: Transform each string into a URL slug form.
* ``join``: Merge together the string values of all selected columns.
* ``upper``: Transform the text to upper case.
* ``lower``: Transform the text to lower case.
* ``strip``: Remove leading and trailing whitespace.
* ``hash``: Generate a SHA1 hash of the given value.

## Tests

The test suite will usually be executed in it's own ``virtualenv`` and perform a
coverage check as well as the tests. To execute on a system with ``virtualenv``
and ``make`` installed, type:

```bash
$ make test
```

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

jsonmapping-0.2.tar.gz (7.2 kB view hashes)

Uploaded Source

Built Distribution

jsonmapping-0.2-py2-none-any.whl (9.4 kB view hashes)

Uploaded Python 2

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page