mapturner

A command line utility for generating consolidated TopoJSON from various data sources. Used for making fast vector maps with D3.

Important links:

• Repository: https://github.com/nprapps/mapturner
• Issues: https://github.com/nprapps/mapturner/issues

Install

You will need to have the following non-Python dependencies installed:

• ogr2ogr (GDAL): brew install ogr2ogr
• topojson: npm install topojson@1.6.27 (topojson 2+ does not work)

mapturner itself can be installed with pip:

pip install mapturner

Developer install process:

git clone git://github.com/nprapps/mapturner.git
cd mapturner
mkvirtualenv mapturner

pip install -r requirements.txt

python setup.py develop

Usage

Define a YAML configuration file, such as the following example. The complete list of valid options is further on in this documentation.

bbox: '77.25 24.28 91.45 31.5'
layers:
    countries:
        type: 'shp'
        path: 'http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_0_countries.zip'
        id-property: 'NAME'
        properties:
            - 'country=NAME'

    cities:
        type: 'shp'
        path: 'http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_populated_places_simple.zip'
        id-property: 'name'
        properties:
            - 'featurecla'
            - 'city=name'
        where: adm0name = 'Nepal' AND scalerank < 8

    quakes:
        type: 'csv'
        path: 'examples/nepal.csv'
        all-properties: True

Then run it!

mapturner input.yaml output.json

The following layer types are currently supported:

• ESRI Shapefile (shp)
• GeoJSON or TopoJSON (json)
• CSV (csv)

How it works

For each layer defined in the configuration file:

• If path is a URL the file will be downloaded and cached locally. (It will not be redownloaded on subsequent runs.)
• If path is to a zipped file it will be unzipped.
• All layers will be clipped to the specified bounding box (using ogr2ogr).
• For each layer, if a where attribute is specified, the layer data will be filtered by that clause.
• For each layer, all fields in the layer not specified in the properties array will be removed (to reduce file size), unless all-properties is specified, in which case all will be kept.
• For each layer, if an id-property is set, data from that property will be set as the identifier for the features in the layer.
• The layer will be converted to TopoJSON.

After each layer has been processed all of them will be concatenated into a single TopoJSON file. Each layer's key name will be used to identify it in the output.

Complete list of configuration options

For all layer types:

• type: The type of layer. Valid types are shp, json (GeoJSON or TopoJSON), and csv. (Required)
• path: The path (relative or absolute) to the layer data file. (Required)
• id-property: A property from the data file to use as the unique identifier for features. See also, the TopoJSON command-line documentation.
• properties: A list of properties from the data to be kept in the output. All other properties are dropped.
• all-properties: If true, then all properties are kept for this layer.
• where: A SQL-like query predicate that will filter the feature data. This This uses exactly the same query syntax as ogr2ogr.

CSV layers only:

• latitude: The name of a column in the data containing the latitude of the point/feature.
• longitude: The name of a column in the data containing the longitude of the point/feature.

Cached data

Cached shapefiles are storied in ~/.mapturner. You may wish to clear this folder periodically to free up space and ensure updated shapefiles are redownloaded.