Random Float Numbers in Python

Scripting
1

Hello, a complete Python beginner here (like minutes ago)
I would like to learn how to create a random list of 20 float values that are a mix of these float values 0.5, 0.75, 1.0, 1.5, 1.75, 2.0 but I don’t want any of the resulting float values next to each other the same.

Can anyone help?
Thanks for your time.

2

random numbers

random stepped numbers

shuffling list

if you are just starting out, it would be best to read through these examples and work with them to get your result.

3

thank you rgr, will do.

4

@FordEarl welcome to python. somemething like this might work:

#import random module
import random

#initialize list with values
val = [0.5, 0.75, 1.0, 1.5, 1.75, 2.0]

#create random index and insert first item in new list
randomindex = random.randint(0, len(val)-1)
randList = [val[randomindex]]

#iterate desired amount of times
for i in range(20):
    #change the index value until its not the same as the previous 
    while randList[-1] == val[randomindex]:
        randomindex = random.randint(0, len(val)-1)
    #append value to new list
    randList.append(val[randomindex])

print randList
5

There probably won’t be a python built-in way to not choose the same value twice (I think that is what you are asking), as that probably isn’t really ‘random’, but it is a useful constraint. Here is another possible solution:

import scriptcontext as sc
import rhinoscriptsyntax as rs
import Rhino as R
import random



choices = [0.5, 0.75, 1.0, 1.5, 1.75, 2.0]
chosen = []


n = 20

# protect from infinite loops
# make sure there is more than 1 choice in choices list
if len(set(choices)) > 1:
    # keep track of last choice
    last_choice = None
    for i in range(n-1):
        # pick a number randomly
        candidate = random.choice(choices)
        # if the candidate is the same as the last choice, try again until it isn't
        # this will go on forever if conditions allow, you may want to limit total attempts
        while candidate == last_choice:
            # print just for fun
            print('duplicate choice on try {}'.format(i))
            candidate = random.choice(choices)
        # candidate should now not be the same as last choice
        chosen.append(candidate)
        # update the last choice
        last_choice = candidate
        
print(chosen)

sample output:

duplicate choice on try 2
duplicate choice on try 4
duplicate choice on try 12
[1.0, 2.0, 0.5, 0.75, 1.5, 0.75, 2.0, 1.0, 1.75, 1.0, 0.5, 2.0, 1.0, 1.5, 1.0, 0.5, 0.75, 2.0, 0.75]