Categorized Style

The categorized style is simillar to QGIS categorized style.

The categorized style is available for all point, line and polygon datasets. This class is inherited from simple style. Below is the example of generating the categorized style for polygon dataset,

# Import and initialized package
from pysld.style import StyleSld
sld = StyleSld(
            style_name='polygonStyle',
            geom_type='polygon',
            attribute_name='USE',
            values=['Agriculture', 'Residential', 'Restaurant', 'Storehouse'],
            color_palette='Spectral_r',
        )

# Generate the categorized style
style = sld.generate_categorized_style()
print(style)

Note: If you want to add the label feature, simple add two more parameters, feature_label=True and attribute_name_label to the StyleSld class.

The above code will generate the following map with corresponding legend,

Which is simillar to following xml,

<StyledLayerDescriptor version="1.0.0" xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd" xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<NamedLayer>
    <Name>polygonStyle</Name>
    <UserStyle>
    <Title>polygonStyle</Title>
    <FeatureTypeStyle>
        <Rule>
            <Name>Agriculture</Name>
            <Title>Agriculture</Title>
            <ogc:Filter>
                <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>USE</ogc:PropertyName>
                    <ogc:Literal>Agriculture</ogc:Literal>
                </ogc:PropertyIsEqualTo>
            </ogc:Filter>
        <PolygonSymbolizer>
            <Fill>
                <CssParameter name="fill">#66c2a5</CssParameter>
                <CssParameter name="fill-opacity">1</CssParameter>
            </Fill>
            <Stroke>
                <CssParameter name="stroke">#333333</CssParameter>
                <CssParameter name="stroke-width">1</CssParameter>
            </Stroke>
        </PolygonSymbolizer>
        </Rule>
        <Rule>
            <Name>Residential</Name>
            <Title>Residential</Title>
            <ogc:Filter>
                <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>USE</ogc:PropertyName>
                    <ogc:Literal>Residential</ogc:Literal>
                </ogc:PropertyIsEqualTo>
            </ogc:Filter>
            <PolygonSymbolizer>
                <Fill>
                    <CssParameter name="fill">#e6f598</CssParameter>
                    <CssParameter name="fill-opacity">1</CssParameter>
                </Fill>
                <Stroke>
                    <CssParameter name="stroke">#333333</CssParameter>
                    <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
            </PolygonSymbolizer>
        </Rule>
        <Rule>
            <Name>Restaurant</Name>
            <Title>Restaurant</Title>
            <ogc:Filter>
                <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>USE</ogc:PropertyName>
                    <ogc:Literal>Restaurant</ogc:Literal>
                </ogc:PropertyIsEqualTo>
            </ogc:Filter>
            <PolygonSymbolizer>
                <Fill>
                    <CssParameter name="fill">#fee08b</CssParameter>
                    <CssParameter name="fill-opacity">1</CssParameter>
                </Fill>
                <Stroke>
                    <CssParameter name="stroke">#333333</CssParameter>
                    <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
            </PolygonSymbolizer>
        </Rule>
        <Rule>
            <Name>Storehouse</Name>
            <Title>Storehouse</Title>
            <ogc:Filter>
                <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>USE</ogc:PropertyName>
                    <ogc:Literal>Storehouse</ogc:Literal>
                </ogc:PropertyIsEqualTo>
            </ogc:Filter>
            <PolygonSymbolizer>
                <Fill>
                    <CssParameter name="fill">#f46d43</CssParameter>
                    <CssParameter name="fill-opacity">1</CssParameter>
                </Fill>
                <Stroke>
                    <CssParameter name="stroke">#333333</CssParameter>
                    <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
            </PolygonSymbolizer>
        </Rule>
    </FeatureTypeStyle>
    </UserStyle>
</NamedLayer>
</StyledLayerDescriptor>

Generate style for PostGIS data

If the shapefile is available in PostgreSQL database, then you need to provide the PostgreSQL connection parameters as below,

# Import and initialized package
from pysld.style import StyleSld
sld = StyleSld(
            style_name='polygonStyle',
            geom_type='polygon',
            attribute_name='USE',
            color_palette='Spectral_r',

            # Postgres connection parameters
            dbname='postgres',
            user='postgres',
            password='admin',
            host='localhost',
            port='5432',
            schema='public',
            pg_table_name='postgres_table_name'
        )

print(sld.values) # It will print the unique values from postgres_table_name table

style = sld.generate_categorized_style()  # Generate the categorized style
print(style) # print categorized style file

The above StyleSld will get the values internally and create the categorized style file for postgres_table_name table.

Available options for categorized style

Options for `StyleSld`
Options	DataType	Default	Description
attribute_name	string		The attribute name for generating the categorized style. The attribute name either provided directly or can be get using `get_attribute_name()` function. See Some additional function for more detail.
values	string		The values based on which the categorized style will be generated. The values either provided directly or can be get using `get_values_from_pg()` function. See Some additional function for more detail.
color_palette	string, list of colors, dict	‘Spectral_r’	The color palette to represent the layer. Check all the available names of color palette here
dbname	string	None	PostgreSQL database name. This parameter will be used for the PostgreSQL connection.
user	string	‘postgres’	PostgreSQL database user. This parameter will be used for the PostgreSQL connection.
password	string	‘admin’	PostgreSQL database user password. This parameter will be used for the PostgreSQL connection.
host	string	‘localhost’	PostgreSQL database host. This parameter will be used for the PostgreSQL connection.
port	integer	5432	PostgreSQL database host. This parameter will be used for the PostgreSQL connection.
schema	string	‘public’	PostgreSQL database data schema. This parameter will be used for get the data from PostgreSQL.
pg_table_name	string	None	PostgreSQL database data table name. This parameter will be used for get the data from PostgreSQL table.

Since the categorized style is inherited from simple style, it supports all the parameters from simple style as well, see Available options for simple style.