The Python's slicing operator can be used with any indexed sequence like strings, lists, ...
syntax --> seq[begin : end : step]
step is optional
defaults are index begin=0, index end=len(seq)-1, step=1
step = -1 reverses sequence

There is a way to ask python what are start, stop and step:

>>> s = slice(None, None, -2) # a slice object corresponding to [::-2]
>>> s.indices(8)
(7, -1, -2) # start, stop, step if the slice is applied to a tuple of length 8

from turtle import *
import random
def allTriMedian (w=300):
speed (0)
vertices = []
point = turtle.Point(x,y)
for i in range (3):
x = random.randint(0,300)
y = random.randint(0,300)
vertices.append(trutle.Point(x,y))
point = turtle.Point(x,y)
triangle = turtle.Polygon(vertices)
a = triangle.side()
b = triangle.side()
c = triangle.side()
m1 = tirangle.median
m2 = triangle.median ...

Hi!
I have two tables, I will call them first-half and second-half (of the year)

Table: first
id jan feb mar apr
-----------------------
2 80 90 70 60
3 50 40 60 30
Table: second
id jan feb mar apr
-----------------------
2 50 70 60 90
3 80 60 50 ...