Placeholders in Python: placing multiple names in an array

I am a beginner in python and learning “Learn Python: The Complete Python Programming Course” using Udemy. I downloaded Python 3.8. All things were good until I reached placeholders:

for i in arr.

I just want to use the function of placeholders in python and complete the task by placing multiple names in an array
I cannot type any of this. May I know why?

I have contacted the concerned person and he is not responding. I am stuck and can’t move ahead in the learning of the course. Please help ASAP.

This image is from the course as is instructed:

This is what I tried to do following the above instructions by the course:

You need to place a colon (":") after the “for” statement:

for i in arr:
    print(sen % (i))

Unfortunately that’s hard to see in the instructions, looks like they made a poor choice of fonts.

Many flow control statements in Python require a colon, the official documentation for the for statement is here.