Python 比较日期范围列表

Question

我有一个包含日期的列表:

dates = [
    {'start': 2015-02-12 08:30, 'end': 2015-02-12 13:30, 'name': 'a'},
    {'start': 2015-02-12 09:00, 'end': 2015-02-12 11:45, 'name': 'b'},
    {'start': 2015-02-12 09:30, 'end': 2015-02-12 10:30, 'name': 'c'},
    {'start': 2015-02-12 10:30, 'end': 2015-02-12 17:30, 'name': 'd'},
    {'start': 2015-02-12 11:00, 'end': 2015-02-12 20:30, 'name': 'e'},
    {'start': 2015-02-12 12:30, 'end': 2015-02-12 18:30, 'name': 'f'},
]

我需要像这样获得输出(将这些日期合并到间隔):

output = [
    {'start': 2015-02-12 08:30, 'end': 2015-02-12 09:00, 'name': 'a'},
    {'start': 2015-02-12 09:00, 'end': 2015-02-12 09:30, 'name': 'a + b'},
    {'start': 2015-02-12 09:30, 'end': 2015-02-12 10:30, 'name': 'a + b + c'},
    {'start': 2015-02-12 10:30, 'end': 2015-02-12 11:00, 'name': 'a + b + d'},
    {'start': 2015-02-12 11:00, 'end': 2015-02-12 11:45, 'name': 'a + b + d + e'},
    {'start': 2015-02-12 11:45, 'end': 2015-02-12 12:30, 'name': 'a + d + e'},
    {'start': 2015-02-12 12:30, 'end': 2015-02-12 13:30, 'name': 'a + d + e + f'},
    {'start': 2015-02-12 13:30, 'end': 2015-02-12 17:30, 'name': 'd + e + f '},
    {'start': 2015-02-12 17:30, 'end': 2015-02-12 18:30, 'name': 'e + f'},
    {'start': 2015-02-12 18:30, 'end': 2015-02-12 20:30, 'name': 'f'},
]

如果其中一项开始 和结束 日期交叉，则每个输出开始 和结束 日期必须按顺序排列它们应该相互合并。

我试图使用循环中的循环

for x, left in enumerate(dates):
    for y, right in enumerate(dates):
        # HERE GOES THE LOGIC..
        # Tried to compare each X and Y item with each other
        # But don't know how to keep used items "in mind"
        # And then create new list to output
        continue

但是没有找到解决这个问题的方法。我正在等待帮助答案，谢谢。

Answer 1

尝试这样:

date_ranges = [
    {'start': '2015-02-12 08:30', 'end': '2015-02-12 13:30', 'name': 'a'},
    # Omitting...
    {'start': '2015-02-12 12:30', 'end': '2015-02-12 18:30', 'name': 'f'},
]

edges = set()
for date_range in date_ranges:
    edges.add(date_range['start'])
    edges.add(date_range['end'])
edges = sorted(list(edges))

intervals = []
for i, edge in enumerate(edges):
    if i == 0:
        continue
    previous_edge = edges[i - 1]
    current_edge = edge
    overlaps = [date_range['name']
                for date_range in date_ranges
                if date_range['start'] <= previous_edge and
                   current_edge <= date_range['end']]
    if overlaps:
        interval = {
            'name': ' + '.join(sorted(overlaps)),
            'start': previous_edge,
            'end': current_edge
        }
        intervals.append(interval)

for interval in intervals:
    print interval

输出:

{'start': '2015-02-12 08:30', 'end': '2015-02-12 09:00', 'name': 'a'}
{'start': '2015-02-12 09:00', 'end': '2015-02-12 09:30', 'name': 'a + b'}
{'start': '2015-02-12 09:30', 'end': '2015-02-12 10:30', 'name': 'a + b + c'}
{'start': '2015-02-12 10:30', 'end': '2015-02-12 11:00', 'name': 'a + b + d'}
{'start': '2015-02-12 11:00', 'end': '2015-02-12 11:45', 'name': 'a + b + d + e'}
{'start': '2015-02-12 11:45', 'end': '2015-02-12 12:30', 'name': 'a + d + e'}
{'start': '2015-02-12 12:30', 'end': '2015-02-12 13:30', 'name': 'a + d + e + f'}
{'start': '2015-02-12 13:30', 'end': '2015-02-12 17:30', 'name': 'd + e + f'}
{'start': '2015-02-12 17:30', 'end': '2015-02-12 18:30', 'name': 'e + f'}
{'start': '2015-02-12 18:30', 'end': '2015-02-12 20:30', 'name': 'e'}