Python在某些点跟踪列表中的索引 [英] Python keeping track of indices in lists at certain points

问题描述

我在迭代方面遇到了一些麻烦，并且在我的列表中的不同点跟踪各种索引和值（我是Python的新手）。

I'm having some trouble with iteration and keeping track of various indices and values at different points in my list (I'm new to Python).

I我正在运行一系列循环，但想确定它们的开始和结束时间。实验从0开始，到50左右结束。

I am running a series of cycles, but want to determine their starts and end times. Experiments starts at around 0 and end at around 50.

这是一个循环列表：

c = [0, 10, 11, 48, 50.5, 0.48, 17, 18, 23, 29, 33, 34.67, 50.1, 0.09, 7, 41, 45, 50]

以下是输出结果的示例：

Here is an example of what the output should look like:

C 1:
Start: (0, 0) # starts at index 0, value 0
End: (4, 50.5) #ends at index 4, value 50.5

C 2:
Start: (5, 0.48)
End: (12, 50.1)

C 3:
Start: (13, 0.09)
End: (17, 50)

我能想到的一种方法是对c进行排序。

One approach I can think of is to sort the c.

c.sort()

这至少会将所有起始值放在列表的开头，将结束值放在列表的末尾。然而，那时我会忘记他​​们原来的指数。有人知道另一种方法吗？

This will at least put all the start values at the beginning of the list and the end values at the end of the list. However, then I would lose track of their original indices. Anyone know of another approach?

编辑：

这是我到目前为止，如果有人可以提供帮助的话修改，它会很棒：

This is what I have so far, if anyone can help modify, it would be great:

min = []
max = []
for i, (first,second) in enumerate(zip(c, c[1:])):
    print(i, first, second)
    if first < second:
        min.append(first)
        continue
    if first > second:
        max.append(first)
        continue

推荐答案

我将任务分开，建立字典， D 增加序列

I divide up the task, build a dictionary, D of the increasing sequences

c = [0, 10, 11, 48, 50.5, 0.48, 17, 18, 23, 29, 33, 34.67, 50.1, 0.09, 7, 41, 45, 50]

D, k = {0: []}, 0

for i, (first, second) in enumerate(zip(c, [0] + c)):
    if first >= second:
        D[k].append((i, first))  # adding increasing to value list in current D[k]
    else:
        k += 1
        D[k] = [(i, first)]  # initializing new D[k] for next sequence

然后以所需格式打印

for k in D:  # sorted(D) safer, dict doesn't guarantee ordering, works here  
    print('C {0}:'.format(k))
    print('Start {0}'.format(D[k][0]))
    print('End   {0}'.format(D[k][-1]), '\n')

C 0:
Start (0, 0)
End   (4, 50.5) 

C 1:
Start (5, 0.48)
End   (12, 50.1) 

C 2:
Start (13, 0.09)
End   (17, 50) 

在我的IDE中很好地打印字典 D 我需要更宽的行限制

to print the dict D nicely in my IDE I needed wider line limit

import pprint

pp = pprint.PrettyPrinter(width=100)
pp.pprint(D)

{0: [(0, 0), (1, 10), (2, 11), (3, 48), (4, 50.5)],
 1: [(5, 0.48), (6, 17), (7, 18), (8, 23), (9, 29), (10, 33), (11, 34.67), (12, 50.1)],
 2: [(13, 0.09), (14, 7), (15, 41), (16, 45), (17, 50)]}

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