ex.py

from functools import reduce
from operator import concat


# ===================================================
# utils
# ===================================================


def select_keys(d: dict, ks: list) -> dict:
    return {k: d[k] for k in ks if k in d}


# ===================================================
# API
# ===================================================


def produce_api_calls(intervals: list) -> list:
    intervals = [select_keys(x, ['vessel', 'start', 'end']) for x in intervals]
    intervals = sorted(intervals, key=lambda x: (x['vessel'], x['start']))
    v_to_intervals = {}
    for interval in intervals:
        vessel, start2, end2 = interval.get('vessel'), interval.get('start'), interval.get('end')
        cur_intervals = v_to_intervals.get(vessel, [])
        if not cur_intervals or cur_intervals[-1].get('end') < start2:
            # empty or no_overlap (end1<start2): add interval
            cur_intervals.append(interval)
            v_to_intervals[vessel] = cur_intervals
        else:
            # overlaps (start2 <= end1): update cur interval with [start1, max(end1, end2)]
            v_to_intervals[vessel][-1]['end'] = max(cur_intervals[-1].get('end'), end2)
    return list(reduce(concat, v_to_intervals.values()))