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    9. Licensing

    Evaluation Limitations and Licensing

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    To study the API quickly, GroupDocs.Metadata offers a Free Trial and a 30-day Temporary License for evaluation, along with several purchase plans.

    Note
    GroupDocs.Metadata also works without a license in trial mode, with certain limitations.

    Purchased License

    After buying, apply the license file or include it as an embedded resource. The license needs to be set:

    • Only once per application
    • Before using any other GroupDocs.Metadata classes

    Evaluation version limitations

    The evaluation download is identical to the purchased one — it simply becomes licensed when you apply a license. Without a license you will face the following limitations:

    APILimitation
    Document properties (PDF, Word, Excel, PowerPoint, Visio, etc.)Only the first 5 properties can be read
    XMP APIOnly the first 2 XMP schemes can be read
    EXIF APIGPS IFD and image thumbnail are unavailable; only the first 5 properties can be read
    IPTC APIOnly the first 5 properties can be read
    ID3v2, Lyrics3, APEv2 tagsOnly the first 5 properties can be read
    QuickTime atomsOnly the first 5 atoms can be read
    File openA maximum of 15 files can be opened, otherwise the API throws an exception
    File saveNot supported in trial mode — save() raises an “Evaluation only” exception

    Licensing

    The license file contains details such as the product name, the number of developers it is licensed to, and the subscription expiry date. It carries a digital signature, so don’t modify the file — even an inadvertent extra line break will invalidate it. Set a license before using the API to avoid the evaluation limitations.

    The license can be loaded from a file or from a stream.

    Applying license from a file 

    import os

from groupdocs.metadata import License


def set_license_from_file():
    # Resolve the license path relative to the current working directory
    license_path = os.path.abspath("./GroupDocs.Metadata.lic")
    if os.path.exists(license_path):
        # Apply the license once, before using any other Metadata API
        license = License()
        license.set_license(license_path)
        print("License set successfully.")
    else:
        print("License file not found; running in evaluation mode.")


if __name__ == "__main__":
    set_license_from_file()

    Applying license from a stream 

    import os

from groupdocs.metadata import License


def set_license_from_stream():
    license_path = os.path.abspath("./GroupDocs.Metadata.lic")
    if os.path.exists(license_path):
        # set_license also accepts a readable binary stream
        with open(license_path, "rb") as stream:
            License().set_license(stream)
        print("License set successfully.")
    else:
        print("License file not found; running in evaluation mode.")


if __name__ == "__main__":
    set_license_from_stream()

    Applying a Metered License

    Note
    You can also set a Metered license as an alternative to a license file. It is a licensing mechanism that bills based on usage. For more details, please refer to the Metered Licensing FAQ.

    The simple steps to use the Metered class:

    1. Create an instance of the Metered class.
    2. Pass the public and private keys to the set_metered_key method.
    3. Perform your processing.
    4. Call Metered.get_consumption_quantity() to get the amount of API requests consumed so far.
    5. Call Metered.get_consumption_credit() to get the credit consumed so far.
    from groupdocs.metadata import Metered


def set_metered_license():
    public_key = "*****"  # Your public key
    private_key = "*****"  # Your private key

    # Guard the sample so it doesn't call the API with placeholder keys
    if "*" in public_key or "*" in private_key:
        print("Provide your real metered keys to activate metered licensing.")
        return

    # Activate metered (pay-as-you-go) billing for this process
    Metered().set_metered_key(public_key, private_key)
    print("Metered license set successfully.")


if __name__ == "__main__":
    set_metered_license()
    Note
    Calling License.set_license multiple times is not harmful but simply wastes processor time. Call it once when the application starts.

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