Swapping consecutive element in a list with a probability in Python-CodePudding

I want to swap consecutive elements in list with a probability. For example, I have this list:

l=[1,2,3,4,5,6,7,8,9,10,11]

I wrote the following code thats swap the consecutive elements

length=len(l) if len(l)%2==0 else len(l)-1
for i in range(0,length,2):
    l[i],l[i 1]=l[i 1],l[I]

The above code results in the following :

l=[2,1,4,3,6,5,8,7,10,9,11]

However, what I want to do is to use a probability for the swap. Let's assume the probability of a swap is 50%. So only 50% of time the swap will happen. Any idea how to achieve this?

CodePudding user response：

If you are writing code that needs some sort of probability, you are guaranteed to only find a possible solution using the random library.

A possible way to solve it is to choose from a choice of true and false and implement the swap when true. Since there are only two possible choices, (true and false), and you are choosing at random(pseudo-random actually), there is a 50% chance of picking each one.

That will look like this:

import random
l=[1,2,3,4,5,6,7,8,9,10,11]
length=len(l) if len(l)%2==0 else len(l)-1
for i in range(0,length,2):
    if random.choice([True, False]): #only swap is true is chosen
        l[i],l[i 1]=l[i 1],l[i]

That should a be a useful workaround. I can't help but wonder why you need that particular behaviour though.