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 ArcGIS Spatial Analyst extension.  | 
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 Pro 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  | Legacy:Raster catalogs are a legacy format and are not supported in ArcGIS Pro.  | 
Raster Catalog Layer  | GPRasterCatalogLayer  | Legacy:Raster catalogs are a legacy format and are not supported in ArcGIS Pro.  | 
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. Note: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.  |