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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 declare_type_info(config):
 """Lookup type info from app configuration."""

    settings = config.registry.settings
    settings['_type_info'] = []
    for line in settings['exports-allowable-types'].splitlines():
        if not line.strip():
            continue
        type_name, type_info = line.strip().split(':', 1)
        type_info = type_info.split(',', 3)
        settings['_type_info'].append((type_name, {
            'type_name': type_name,
            'file_extension': type_info[0],
            'mimetype': type_info[1],
            'user_friendly_name': type_info[2],
            'description': type_info[3],
            }))