Question

Im trying to add 5 to this vector if a number in the vector is less then 4. I feel like im pretty close but it isnt running correctly. Can anyone give me some help adding 5 to any value less then 4 in the vector?

from pylab import * 
numberlist = [3.2,6,7.8,1,3,2.5]
def x(numberlist):
    for num in numberlist:
        if num > 4:
            print(num)
        else :
            print(num + 5)
print x([3.2,6,7.8,1,3,2.5])

Answer 1

What you have does exactly what you’re describing. Looks like you’re new to python, possibly new to programming in general.

The code is a bit confusing for the following reasons.

1. You define a global variable named numberlist and assign it an array of numbers.
2. The parameter for you function x is named numberlist again.
3. When calling x, you pass an array of the same values you assigned to the global variable numberlist in the beginning.

Important points to note:

• The global variable numberlist and x‘s parameter named numberlist are two TOTALLY DIFFERENT VARIABLES. The effect you have is that the global variable numberlist isn’t accessible inside of your function x. You’re not actually using the global variable numberlist anywhere.
• If you wanted to use the global variable numberlist and pass it to x, instead of x([3.2,6,7.8,1,3,2.5]), you would just do x(numberlist).
• You should rename x‘s numberlist parameter to something else. mylist for example.
• You really don’t need the import statement at the top.

Taking those into account, your code is more readable as follows:

def x(mylist):
    for num in mylist:
        if num > 4:
            print(num)
        else :
            print(num + 5)
numberlist = [3.2,6,7.8,1,3,2.5]
print x(numberlist)