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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def list(ctx):
 """List active data packages."""

    log.debug('chemdataextractor.data.list')
    click.echo('Downloaded\tPackage')
    for package in PACKAGES:
        click.echo('%s\t%s' % (package.local_exists(), package.path))