How do add items from a list in an iterative fashion to two different lists?-CodePudding

I have a time-series consisting of numeric data points, say in form of a list:

x = [924, -5, 24, 1, 0, 242, -5, 42, 5, 1, -9, 50, 3, 432, 0, -5, 4]

Now I would like to achieve the following aim that I describe in three steps:

The first two values from the list, x(1) and x(2), namely 924 and -5, should be added to the two lists below, respectively.

x_list = []
y_list = []

This is to say that x(1) (=924) should be added to x_list and x(2) (=-5) to y_list.

This would be managable for me, but since my aim continues as follows, I am currently unable to solve this in Python.

The second aim is to take the next two values or "pairs" of the list x, namely x(2) and x(3), and add again them to x_listand y_list, respectively. Now (x2) goes to x_list, and x(3) to y_list.
Finally, I would like to repeat this step, i.e., adding x(3) to x_list and x(4) to y_list and so on, until the end of the time-series x is reached.

I assume that I have to program a function using def. But I don't understand how to set up the code for this aim. Here is the current state of my code.

import numpy as np
import matplotlib.pyplot. as plt

x = [924, -5, 24, 1, 0, 242, -5, 42, 5, 1, -9, 50, 3, 432, 0, -5, 4]

x_results = []
y_results = []

for t in Timeseries:
next_n = # This is where I am stuck, struggling to find the correct code
next_y = 
x_results.append(next_x)
y_results.append(next_y)

plt.plot(x_results, y_results, "bo")
plt.show()

CodePudding user response：

You can use two slices:

mylist = [924, -5, 24, 1, 0, 242, -5, 42, 5, 1, -9, 50, 3, 432, 0, -5, 4]

x_list = mylist[:-1]
y_list = mylist[1:]

CodePudding user response：

for python ≥ 3.10, this is the job of itertools.pairwise:

from itertools import pairwise
x, y = zip(*pairwise(mylist))

output:

x
(924, -5, 24, 1, 0, 242, -5, 42, 5, 1, -9, 50, 3, 432, 0, -5),

y
(-5, 24, 1, 0, 242, -5, 42, 5, 1, -9, 50, 3, 432, 0, -5, 4)

for python < 3.10, the recipe for pairwise is:

from itertools import tee

def pairwise(iterable):
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)