Question

我有一个表示年范围的整数对的列表，需要计算连续（一年内）对的联合范围。

示例输入：

ts_list = [[1777, 1777], [1778, 1783], [1786, 1791], [1792, 1795]]

所需的输出

[[1777, 1781], [1786, 1795]]

我尝试了while和while循环，并且可以在第一个脱节之前获得并集，但是我对如何正确进行迭代感到困惑-例如产生

的新列表

[[1777, 1783], [1778, 1783], [1786, 1795]]

然后返回类型错误：'int' object is not subscriptable"。第一对和第三对是正确的，但第二对是无关的

ts_list = [[1777, 1777], [1778, 1781], [1786, 1791], [1792, 1795]]
newlist=[]
last = ts_list[len(ts_list)-1][1]
for x in range(len(ts_list)):
   ts=ts_list[x]
   start = ts[0]
   end = ts[1]
   ts_next = ts_list[x+1] if x<len(ts_list)-1 else last
   if ts_next[0]-end > 1:
       # next is disjoint, break out
       newlist.append([start,end])
   else:
       # next is contiguous (within 1 year)
       newlist.append([start,ts_next[1]])

Answer 1

您可以这样做：

ts_list = [[1777, 1777], [1778, 1781], [1786, 1791], [1792, 1795]]

# We start with the first range
out = [ts_list[0]]
for start, end in ts_list[1:]:
    if start <= out[-1][1] + 1:
        # if the new range starts at most one year
        # after the end of the previous one, we extend it:
        out[-1][1] = end
    else:
        # otherwise, we append this new range to the output
        out.append([start, end])

print(out)

# [[1777, 1781], [1786, 1795]]

Answer 2

使用集合/列表理解：

ts_list = [[1777, 1777], [1778, 1781], [1786, 1791], [1792, 1795]]


# Get all years that are contained in one of the date ranges, including start and end year.
# Using a set ensures that each year appears only once.

all_years = {y for years in ts_list for y in range(years[0], years[1] + 1)}


# Get start years (years where the previous year is not in all_years)
# and end years (years where the following year is not in all_years).

start_years = [y for y in all_years if y - 1 not in all_years]
end_years = [y for y in all_years if y + 1 not in all_years]


# Combine start and end years. To match the right ones, sort first.

start_years.sort()
end_years.sort()
result = [[start_year, end_year] for start_year, end_year in zip(start_years, end_years)]


print(result)
# [[1777, 1781], [1786, 1795]]

如何迭代整数对列表，计算新的“联合对”

2 个答案: