Returning a value based on index number of each element in a list

Question

I am trying to identify the first element, last element, and other elements in a python list using a function.
If it’s the first element, I want 0 to be returned, if it’s the last element I want -1 to be returned, every other element should return 2.

I can achieve this without using a function but when I use a function, I don’t get the desired result.
Please help me with this. Thanks in advance

What I have so far can be seen in the codes and screenshots below
here is the code without using a function

a= [1,2,3,4,5,6]
    for i, x in enumerate(a):
        if i==0:
            number=0 
        elif i==len(a)-1:
            number=-1
        else:
            number=2 
        print (number)

here is the desired output, it is gotten when function is not used

here is the same code in a function

def cs():
    a= [1,2,3,4,5,6]
    for i, x in enumerate(a):
        if i==0:
            number=0 
        elif i==len(a)-1:
            number=-1
        else:
            number=2 
        print (number)
        return (number)
cs()

here is the output of the function. it returns only one index instead of six

If i try having the print/return statement outside the for loop, only the last element returns a value.

def cs():
    a= [1,2,3,4,5,6]
    for i, x in enumerate(a):
        if i==0:
            number=0 
        elif i==len(a)-1:
            number=-1
        else:
            number=2 
    print (number)
    return (number)
cs()

here is the output of the function with the print/return statement outside the for loop

Asked By: Cassie

||

Source

Answer 1

Your query- is it possible to iterate through the whole list and still use a return statement?

Instead of return we use yield to go through whole list.

def generator():
    a= [1,2,3,4,5,6]
    for i,x in enumerate(a):
        if i==0:
            yield 0 
        elif i==len(a)-1:
            yield -1
        else:
            yield 2

gen_object = generator()
print(type(gen_object))
for i in gen_object:
   print(i)

Output:-

<class 'generator'>
0
2
2
2
2
-1

Answered By: Yash Mehta

Returning a value based on index number of each element in a list

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