In a Python toolbox, the parameter's datatype property is set using the Parameter class in the getParameterInfo method.
def getParameterInfo(self):
    # Define parameter definitions
    # First parameter
    param0 = arcpy.Parameter(
        displayName="Input workspace",
        name="in_workspace",
        datatype="DEWorkspace",
        parameterType="Required",
        direction="Input")Composite data types
You may need a parameter to accept multiple data types, often referred to as a composite data type. In a Python toolbox, composite data types are defined by assigning a list of data types to the parameter's datatype property. In the following example, a parameter is defined that accepts a raster dataset or a feature class:
def getParameterInfo(self):
    # Define parameter definitions
    # First parameter
    param0 = arcpy.Parameter(
        displayName="Input Raster Dataset",
        name="in_rasterdataset",
        datatype=["DERasterDataset", "DEFeatureClass"],
        parameterType="Required",
        direction="Input")Data types
Every tool parameter has an associated data type as shown in the following table:
| Data type | datatype keyword | Description | 
|---|---|---|
| 3D Tiles Layer | GP3DTilesLayer | A 3D tiles layer references a tile set that defines an integrated mesh or 3D object type data in a hierarchical data structure. | 
| Address Locator | DEAddressLocator | A dataset used for geocoding that stores the address attributes, associated indexes, and rules that define the process for translating nonspatial descriptions of places to spatial data. | 
| Analysis Cell Size | analysis_cell_size | The cell size used by raster tools. | 
| Any Value | GPType | A data type that accepts any value. | 
| ArcMap Document | DEMapDocument | A file that contains one map, its layout, and its associated layers, tables, charts, and reports. | 
| Areal Unit | GPArealUnit | An areal unit type and value, such as square meter or acre. | 
| Boolean | GPBoolean | A Boolean value. | 
| CAD Drawing Dataset | DECadDrawingDataset | A vector data source combined with feature types and symbology. The dataset cannot be used for feature class-based queries or analysis. | 
| Calculator Expression | GPCalculatorExpression | A calculator expression. | 
| Catalog Layer | GPCatalogLayer | A collection of references to different data types. The data types can be from different locations and are managed and visualized dynamically as layers based on location, time, and other attributes. | 
| Catalog Root | DECatalogRoot | The top-level node in the Catalog tree. | 
| Cell Size | GPSACellSize | The cell size used by the Extensión ArcGIS Spatial Analyst. | 
| Cell Size XY | GPCellSizeXY | The size that defines the two sides of a raster cell. | 
| Composite Layer | GPCompositeLayer | A reference to several children layers, including symbology and rendering properties. | 
| Compression | GPSAGDBEnvCompression | The type of compression used for a raster. | 
| Coordinate System | GPCoordinateSystem | A reference framework, such as the UTM system consisting of a set of points, lines, or surfaces, and a set of rules used to define the positions of points in two- and three-dimensional space. | 
| Coordinate Systems Folder | DESpatialReferencesFolder | A folder on disk storing coordinate systems. | 
| Coverage | DECoverage | A coverage dataset, a proprietary data model for storing geographic features as points, arcs, and polygons with associated feature attribute tables. | 
| Coverage Feature Class | DECoverageFeatureClasses | A coverage feature class, such as point, arc, node, route, route system, section, polygon, and region. | 
| Data Element | DEType | A dataset visible in ArcCatalog. | 
| Data File | GPDataFile | A data file. | 
| Database Connections | DERemoteDatabaseFolder | The database connection folder in ArcCatalog. | 
| Dataset | DEDatasetType | A collection of related data, usually grouped or stored together. | 
| Date | GPDate | A date value. | 
| dBASE Table | DEDbaseTable | Attribute data stored in dBASE format. | 
| Decimate | GP3DADecimate | A subset of nodes of a TIN to create a generalized version of that TIN. | 
| Diagram Layer | GPDiagramLayer | A diagram layer. | 
| Disk Connection | DEDiskConnection | An access path to a data storage device. | 
| Double | GPDouble | Any floating-point number stored as a double precision, 64-bit value. | 
| Encrypted String | GPEncryptedString | An encrypted string for passwords. | 
| Envelope | GPEnvelope | The coordinate pairs that define the minimum bounding rectangle in which the data source resides. | 
| Evaluation Scale | GPEvaluationScale | The scale value range and increment value applied to inputs in a weighted overlay operation. | 
| Extent | GPExtent | The coordinate pairs that define the minimum bounding rectangle (x-minimum, y-minimum and x-maximum, y-maximum) of a data source. All coordinates for the data source are within this boundary. | 
| Extract Values | GPSAExtractValues | An extract values parameter. | 
| Feature Class | DEFeatureClass | A collection of spatial data with the same shape type: point, multipoint, polyline, and polygon. | 
| Feature Dataset | DEFeatureDataset | A collection of feature classes that share a common geographic area and the same spatial reference system. | 
| Feature Layer | GPFeatureLayer | A reference to a feature class, including symbology and rendering properties. | 
| Feature Set | GPFeatureRecordSetLayer | Interactive features that draw the features when the tool is run. | 
| Field | Field | A column in a table that stores the values for a single attribute. | 
| Field Info | GPFieldInfo | The details about a field in a field map. | 
| Field Mappings | GPFieldMapping | A collection of fields in one or more input tables. | 
| File | DEFile | A file on disk. | 
| Folder | DEFolder | A location on disk where data is stored. | 
| Formulated Raster | GPRasterFormulated | A raster surface whose cell values are represented by a formula or constant. | 
| Fuzzy function | GPSAFuzzyFunction | The algorithm used in fuzzification of an input raster. | 
| Geodataset | DEGeodatasetType | A collection of data with a common theme in a geodatabase. | 
| GeoDataServer | DEGeoDataServer | A coarse-grained object that references a geodatabase. | 
| Geometric Network | DEGeometricNetwork | A linear network represented by topologically connected edge and junction features. Feature connectivity is based on their geometric coincidence. | 
| Geostatistical Layer | GPGALayer | A reference to a geostatistical data source, including symbology and rendering properties. | 
| Geostatistical Search Neighborhood | GPGASearchNeighborhood | The searching neighborhood parameters for a geostatistical layer are defined. | 
| Geostatistical Value Table | GPGAValueTable | A collection of data sources and fields that define a geostatistical layer. | 
| GlobeServer | DEGlobeServer | A Globe server. | 
| GPServer | DEGPServer | A geoprocessing server. | 
| Graph | GPGraph | A graph. | 
| Graph Data Table | GPGraphDataTable | A graph data table. | 
| Group Layer | GPGroupLayer | A collection of layers that appear and act as a single layer. Group layers make it easier to organize a map, assign advanced drawing order options, and share layers for use in other maps. | 
| Horizontal Factor | GPSAHorizontalFactor | The relationship between the horizontal cost factor and the horizontal relative moving angle. | 
| Image Service | DEImageServer | An image service. | 
| Index | Index | A data structure used to speed the search for records in geographic datasets and databases. | 
| INFO Expression | GPINFOExpression | A syntax for defining and manipulating data in an INFO table. | 
| INFO Item | GPArcInfoItem | An item in an INFO table. | 
| INFO Table | DEArcInfoTable | A table in an INFO database. | 
| Internet Tiled Layer | GPInternetTiledLayer | An internet tiled layer. | 
| KML Layer | GPKMLLayer | A KML layer. | 
| LAS Dataset | DELasDataset | A LAS dataset stores reference to one or more LAS files on disk as well as to additional surface features. A LAS file is a binary file that stores airborne lidar data. | 
| LAS Dataset Layer | GPLasDatasetLayer | A layer that references a LAS dataset on disk. This layer can apply filters on lidar files and surface constraints referenced by a LAS dataset. | 
| Layer | GPLayer | A reference to a data source, such as a shapefile, coverage, geodatabase feature class, or raster, including symbology and rendering properties. | 
| Layer File | DELayer | A layer file stores a layer definition, including symbology and rendering properties. | 
| Line | GPLine | A shape, straight or curved, defined by a connected series of unique x,y-coordinate pairs. | 
| Linear Unit | GPLinearUnit | A linear unit type and value such as meter or feet. | 
| Long | GPLong | An integer number value. | 
| M Domain | GPMDomain | A range of lowest and highest possible value for m-coordinates. | 
| Map | GPMap | An ArcGIS AllSource map. | 
| MapServer | DEMapServer | A map server. | 
| Map Server Layer | GPMapServerLayer | A map server layer. | 
| Mosaic Dataset | DEMosaicDataset | A collection of raster and image data that allows you to store, view, and query the data. It is a data model in the geodatabase used to manage a collection of raster datasets (images) stored as a catalog and viewed as a mosaicked image. | 
| Mosaic Layer | GPMosaicLayer | A layer that references a mosaic dataset. | 
| Neighborhood | GPSANeighborhood | The shape of the area around each cell used to calculate statistics. | 
| Network Analyst Class FieldMap | NAClassFieldMap | Mapping between location properties in a Network Analyst layer (such as stops, facilities, and incidents) and a point feature class. | 
| Network Analyst Hierarchy Settings | GPNAHierarchySettings | A hierarchy attribute that divides hierarchy values of a network dataset into three groups using two integers. The first integer sets the ending value of the first group; the second number sets the beginning value of the third group. | 
| Network Analyst Layer | GPNALayer | A group layer used to express and solve network routing problems. Each sublayer held in memory in a Network Analyst layer represents some aspect of the routing problem and the routing solution. | 
| Network Data Source | GPNetworkDataSource | A network data source can be a local dataset specified either using its catalog path or a layer from a map, or it can be a URL to a portal. | 
| Network Dataset | DENetworkDataset | A collection of topologically connected network elements (edges, junctions, and turns), derived from network sources and associated with a collection of network attributes. | 
| Network Dataset Layer | GPNetworkDatasetLayer | A reference to a network dataset, including symbology and rendering properties. | 
| Network Travel Mode | NetworkTravelMode | A dictionary of travel mode objects. | 
| Oriented Imagery Layer | GPOrientedImageryLayer | A collection of camera locations with image metadata. | 
| Pairwise Weights Table | GPPairwiseWeightsTable | A table of a pairwise comparison matrix containing evaluations for each of the pairs for the input variables. | 
| Parcel Fabric For ArcMap | DECadastralFabric | A dataset used for the storage, maintenance, and editing of a continuous surface of connected parcels or parcel network. | 
| Parcel Fabric Layer | GPCadastralFabricLayer | A layer referencing a parcel fabric on disk. This layer works as a group layer organizing a set of related layers under a single layer. | 
| Point | GPPoint | A pair of x,y-coordinates. | 
| Polygon | GPPolygon | A connected sequence of x,y-coordinate pairs in which the first and last coordinate pair are the same. | 
| Projection File | DEPrjFile | A file storing coordinate system information for spatial data. | 
| Pyramid | GPSAGDBEnvPyramid | Specifies whether pyramids are built. | 
| Radius | GPSARadius | The surrounding points that are used for interpolation. | 
| Random Number Generator | GPRandomNumberGenerator | The seed and the generator to use when creating random values. | 
| Raster Band | DERasterBand | A layer in a raster dataset. | 
| Raster Calculator Expression | GPRasterCalculatorExpression | A raster calculator expression. | 
| Raster Catalog | DERasterCatalog | Heredado:Raster catalogs are a legacy format and are not supported in ArcGIS AllSource. | 
| Raster Catalog Layer | GPRasterCatalogLayer | Heredado:Raster catalogs are a legacy format and are not supported in ArcGIS AllSource. | 
| Raster Data Layer | GPRasterDataLayer | A raster data layer. | 
| Raster Dataset | DERasterDataset | A single dataset built from one or more rasters. | 
| Raster Layer | GPRasterLayer | A reference to a raster, including symbology and rendering properties. | 
| Raster Statistics | GPSAGDBEnvStatistics | Specifies whether raster statistics will be built. | 
| Raster Type | GPRasterBuilder | Raster data is added to a mosaic dataset by specifying a raster type. The raster type identifies metadata, such as georeferencing, acquisition date, and sensor type, with a raster format. | 
| Record Set | GPRecordSet | An interactive table. Provide the table values when the tool is run. | 
| Relationship Class | DERelationshipClass | The details about the relationship between objects in the geodatabase. | 
| Remap | GPSARemap | A table that defines how raster cell values are reclassified. | 
| Route Measure Event Properties | GPRouteMeasureEventProperties | The fields on a table that describe events measured by a linear reference route system. | 
| Scene Service Layer | GPSceneServiceLayer | A scene service layer. | 
| Schematic Dataset | DESchematicDataset | A collection of schematic diagram templates and schematic feature classes that share the same application domain, for example, water or electrical. | 
| Schematic Diagram | DESchematicDiagram | A schematic diagram. | 
| Schematic Diagram Class | DESchematicDiagramClass | A schematic diagram class. | 
| Schematic Folder | DESchematicFolder | A schematic folder. | 
| Schematic Layer | GPSchematicLayer | A composite layer composed of feature layers based on the schematic feature classes associated with the template on which the schematic diagram is based. | 
| SemiVariogram | GPSASemiVariogram | The distance and direction representing two locations used to quantify autocorrelation. | 
| ServerConnection | DEServerConnection | A server connection. | 
| Shapefile | DEShapeFile | Spatial data in shapefile format. | 
| Spatial Reference | GPSpatialReference | The coordinate system used to store a spatial dataset, including the spatial domain. | 
| SQL Expression | GPSQLExpression | A syntax for defining and manipulating data from a relational database. | 
| String | GPString | A text value. | 
| String Hidden | GPStringHidden | A string that is masked by asterisk characters. Nota:The text is not encrypted when used in scripting. | 
| Table | DETable | Tabular data. | 
| Table View | GPTableView | A representation of tabular data for viewing and editing purposes stored in memory or on disk. | 
| Terrain Layer | GPTerrainLayer | A reference to a terrain, including symbology and rendering properties. It’s used to draw a terrain. | 
| Text File | DETextfile | A text file. | 
| Tile Size | GPSAGDBEnvTileSize | The width and height of data stored in block. | 
| Time configuration | GPSATimeConfiguration | The time periods used for calculating solar radiation at specific locations. | 
| Time Unit | GPTimeUnit | A time unit type and value such as minutes or hours. | 
| TIN | DETin | A vector data structure that partitions geographic space into contiguous, nonoverlapping triangles. The vertices of each triangle are sample data points with x-, y-, and z-values. | 
| Tin Layer | GPTinLayer | A reference to a TIN, including topological relationships, symbology, and rendering properties. | 
| Tool | DETool | A geoprocessing tool. | 
| Toolbox | DEToolbox | A geoprocessing toolbox. | 
| Topo Features | GPSATopoFeatures | Features that are input to the interpolation. | 
| Topology | DETopology | A topology that defines and enforces data integrity rules for spatial data. | 
| Topology Layer | GPTopologyLayer | A reference to a topology, including symbology and rendering properties. | 
| Transformation Function | GPSATransformationFunction | A Spatial Analyst transformation function. | 
| Trajectory Layer | GPTrajectoryLayer | A layer that references a trajectory dataset. | 
| Utility Network | DEUtilityNetwork | A utility network. | 
| Utility Network Layer | GPUtilityNetworkLayer | A utility network layer. | 
| GPValueTable | A collection of columns of values. | |
| Variant | GPVariant | A data value that can contain any basic type: Boolean, date, double, long, and string. | 
| Vector Tile Layer | GPVectorLayer | A vector tile layer. | 
| Vertical Factor | GPSAVerticalFactor | The relationship between the vertical cost factor and the vertical, relative moving angle. | 
| VPF Coverage | DEVPFCoverage | Spatial data stored in Vector Product Format. | 
| VPF Table | DEVPFTable | Attribute data stored in Vector Product Format. | 
| WCS Coverage | DEWCSCoverage | Web Coverage Service (WCS) is an open specification for sharing raster datasets on the web. | 
| Weighted Overlay Table | GPSAWeightedOverlayTable | A table with data to combine multiple rasters by applying a common measurement scale of values to each raster, weighing each according to its importance. | 
| Weighted Sum | GPSAWeightedSum | Data for overlaying several rasters, each multiplied by their given weight and summed. | 
| WMS Map | DEWMSMap | A Web Map Service (WMS) specification map. | 
| Workspace | DEWorkspace | A container such as a geodatabase or folder. | 
| XY Domain | GPXYDomain | A range of lowest and highest possible values for x,y-coordinates. | 
| Z Domain | GPZDomain | A range of lowest and highest possible values for z-coordinates. |