example_load.py

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#! /usr/bin/env oagpython3
 
"""
@file example_load.py
@brief Demonstrates reading an SDDS file using the SDDS Python module
@details
This script showcases how to utilize the SDDS Python module to read and display
the contents of an SDDS (Self Describing Data Set) file. The script performs the
following operations:
 
1. Initializes an SDDS object.
2. Loads an existing SDDS file specified by the user.
3. Determines and displays the file mode (binary or ASCII).
4. Prints the description text and contents if available.
5. Lists all parameters, arrays, and columns along with their metadata.
6. Iterates through each loaded page and displays the data for parameters,
   arrays, and columns.
 
Usage:
    Ensure that the SDDS Python module is installed and the input SDDS file
    (`output_all_data_types.sdds`) is present in the working directory.
"""
 
import sdds
 
def main():
    # Specify the input SDDS file.
    # This example uses the output file generated by the example_save.py script
    input_file = "output_all_data_types.sdds"
    
    # Load the SDDS file into the SDDS object
    sdds_obj = sdds.load(input_file)
 
    # Determine and display the file mode: Binary or ASCII
    if sdds_obj.mode == sdds.SDDS_BINARY:
        print("SDDS file mode: SDDS_BINARY")
    else:
        print("SDDS file mode: SDDS_ASCII")
    
    # Display the description text if available
    if sdds_obj.description[0]:
        print(f"SDDS file description text: {sdds_obj.description[0]}")
    
    # Display additional description contents if available
    if sdds_obj.description[1]:
        print(f"SDDS file description contents: {sdds_obj.description[1]}")
    
    # Check and print parameter definitions if any are present
    if sdds_obj.parameterName:
        print("\nParameters:")
        for i, definition in enumerate(sdds_obj.parameterDefinition):
            name = sdds_obj.parameterName[i]
            datatype = sdds.sdds_data_type_to_string(definition[4])
            units = definition[1]
            description = definition[2]
            print(f"  {name}")
            print(f"    Datatype: {datatype}", end="")
            if units:
                print(f", Units: {units}", end="")
            if description:
                print(f", Description: {description}", end="")
            print("")  # Newline for readability
    
    # Check and print array definitions if any are present
    if sdds_obj.arrayName:
        print("\nArrays:")
        for i, definition in enumerate(sdds_obj.arrayDefinition):
            name = sdds_obj.arrayName[i]
            datatype = sdds.sdds_data_type_to_string(definition[5])
            units = definition[1]
            description = definition[2]
            dimensions = definition[7]
            print(f"  {name}")
            print(f"    Datatype: {datatype}, Dimensions: {dimensions}", end="")
            if units:
                print(f", Units: {units}", end="")
            if description:
                print(f", Description: {description}", end="")
            print("")  # Newline for readability
    
    # Check and print column definitions if any are present
    if sdds_obj.columnName:
        print("\nColumns:")
        for i, definition in enumerate(sdds_obj.columnDefinition):
            name = sdds_obj.columnName[i]
            datatype = sdds.sdds_data_type_to_string(definition[4])
            units = definition[1]
            description = definition[2]
            print(f"  {name}")
            print(f"    Datatype: {datatype}", end="")
            if units:
                print(f", Units: {units}", end="")
            if description:
                print(f", Description: {description}", end="")
            print("")  # Newline for readability
    
    # Iterate through each loaded page and display parameter, array, and column data
    for page in range(sdds_obj.loaded_pages):
        print(f"\nPage: {page + 1}")
        
        # Display parameter data for the current page
        for i, name in enumerate(sdds_obj.parameterName):
            value = sdds_obj.parameterData[i][page]
            print(f"  Parameter '{name}': {value}")
        
        # Display array data for the current page
        for i, name in enumerate(sdds_obj.arrayName):
            value = sdds_obj.arrayData[i][page]
            print(f"  Array '{name}': {value}")
        
        # Display column data for the current page
        for i, name in enumerate(sdds_obj.columnName):
            value = sdds_obj.columnData[i][page]
            print(f"  Column '{name}': {value}")
 
    # Opitonally delete the SDDS object
    del sdds_obj
    
if __name__ == "__main__":
    main()