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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 commit_history(filename):
 """Retrieve the commit history for a given filename. Keyword Arguments: :filename: (str) -- full name of the file Returns: list of dicts -- list of commit if the file is not found, returns an empty list """

    result = []
    repo = Repo()
    for commit in repo.head.commit.iter_parents(paths=_delta_dir() + filename):
        result.append({'date':
                       datetime.fromtimestamp(commit.committed_date +
                                              commit.committer_tz_offset),
                       'hexsha': commit.hexsha})
    return result