How can I iterate through two lists and compare the values of each in Python?

Suppose I have the following lists:

x = [0.5, 0.9, 0.1, 0.3, 0.6]

y = [0.4, 0.3, 0.6, 0.1, 0.9]

I want to write a function that iterates through the list and compares each value in order.

 def compare_numbers(prob,thresh):
 output = []
 for x, y in zip(prob, thresh):
   if x >= y:
    output.append(1)
   else:
    output.append(0)
  return output

  compare_numbers(x,y)

This gives me Type Error: 'float' object is not iterable'

Why is this?

I would expect the output to look like this: [1, 1, 0, 1, 0]

Is there anyway I could write this function such that if the “threshold” value was only one digit it would still work?

My current code to make the latter function is:

def compare_numbers(prob, thresh):
 output = []
 for n in prob:
  if n >= thresh:
   output.append(1)
  else:
    output.append(0)
return output

compare_numbers(x,y)

Yet this returns the Type Error: TypeError: '>=' not supported between instances of 'int' and 'list' when thresh is a list.

Answer

The problem is that you are comparing the value n from prob with the entire list thresh. What you need to do is to also iterate over thresh. Here is a small fix that will allow your code to work:

   def compare_numbers(prob, thresh):
     output = []
     for n in range(len(prob)):
       if prob[n] >= thresh[n]:
         output.append(1)
       else:
         output.append(0)
     return output