Pardon if I have been posting series of questions. Newbie Python learner here, and am going through PCEP materials, and having some questions along the way… Thank you in advance for the help. In these two codes, I confused why the answer is such: Code 1: my_list = [0,1,2,3] x = 1 for elem ... More on discuss.python.org

If you just learned loops, what you are looking for is a for loop. Since you mentioned functions we'll go ahead and make this a function. What do we want in our function? Well, we want it to take a list and return the multiplied values. NOTE: For simplicity, I'm going to assume your list is valid (numbers only), but in an actual function you'd want some error checking. How does our function definition look? def multiply_list_values(number_list): OK! We have the basics. So let's think through what we want to do. We want to go through each value of the list and multiply it with the previous total. We could also easily use recursion here, but since you didn't mention learning that I won't. It's fairly simple in either case. So how do you go through all the values of a list? Using a for...in loop. It will look something like this: def multiply_list_values(number_list): for number in number_list: print(number) If you run this, and have number_list as a list of numbers, you will see each individual number printed out in order. That's a good start, but it doesn't really do what we want. So lets think about our base case, where we want the very first number multiplied. If we were adding, we'd start at 0, but since we're multiplying, we need to start with 1, as 1 * X = X. Let's see how this looks: def multiply_list_values(number_list): result = 1 for number in number_list: print(result * number) Well, we get the same thing. What we need to do is multiply the value by each subsequent number to continually increment the result. How do we do this? We can assign a variable the result of a calculation involving itself. This doesn't work like a math equation. For example, if you had a variable x = 1 and wanted to add 2 to that value, you could do this: x = x + 2 and now x would be 3. So let's try the same thing with multiplication: def multiply_list_values(number_list): result = 1 for number in number_list: result = result * number print(result) So what do we have now? If you run this, you'll see the multiplied values getting higher and higher, and it will run through the whole list. Great! That's exactly what we want. Incidentally, this is such a common thing to do there is a shorthand way built into Python to make this easier. Instead of result = result * number you can remove the result on the right side and put your math operator before the equals sign like this: result *= number. This does the exact same thing. In our x example, you could change the x = x + 2 to x += 2 for the same result. Now that the math is finished, we just need to return the result after the loop, making our simplified and final function look like this (with test usage): def multiply_list_values(number_list): result = 1 for number in number_list: result = result * number return result def main(): number_list = [1, 2, 3, 4, 5] print(multiply_list_values(number_list)) # Output # 120 if __name__ == '__main__': main() There are many problems in Python (and programming in general) that can be solved this way. The for..in loop is extremely useful and can be used for all sorts of operations, not just mathematical ones, so keep it in mind whenever you want to do operations on every element of a list or dictionary. Let me know if you have questions! More on reddit.com

Firstly, the i += 1 part of your code does nothing. Second, the range function can take up to three arguments. When you pass all three, the first is the starting number, the second is the last number (but remember that Python uses half-open intervals), and the last is the step. So you'd do for i in range(0, 4, 2): print(i) More on reddit.com

How is this working and for loop increment doesn’t work? for i in range(0,10): if i == 3: i = i + 1 continue print(i) More on stackoverflow.com