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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 sitespeptidesproteins(df, site_localization_probability=0.75):
 """ Generate summary count of modified sites, peptides and proteins in a processed dataset ``DataFrame``. Returns the number of sites, peptides and proteins as calculated as follows: - `sites` (>0.75; or specified site localization probability) count of all sites > threshold - `peptides` the set of `Sequence windows` in the dataset (unique peptides) - `proteins` the set of unique leading proteins in the dataset :param df: Pandas ``DataFrame`` of processed data :param site_localization_probability: ``float`` site localization probability threshold (for sites calculation) :return: ``tuple`` of ``int``, containing sites, peptides, proteins """


    sites = filters.filter_localization_probability(df, site_localization_probability)['Sequence window']
    peptides = set(df['Sequence window'])
    proteins = set([str(p).split(';')[0] for p in df['Proteins']])
    return len(sites), len(peptides), len(proteins)