def extract_from_dictionary(ls_of_dictionaries, key_name):
    """
    Iterates through a list of dictionaries and, based on the inserted key name, extracts that data.

    :param: ls_of_dictionaries: a list of dictionaries
    :param: key_name: a string with ('') that indexes which set of the dictionary you want to extract

    :returns: list with the specified (keyed) datatype


    """

    #index = []
    partic_name = []
    data_element = []

    for index, dictionary in enumerate(ls_of_dictionaries):
            data = dictionary[key_name]
            partic_name = dictionary['partic_number']
            data_element.append(data)

    return(data_element)