Member Avatar for abcdr

I am trying to square each number in the list under nums. But I don't know how to do it. I got this so far:

def squareEach(nums):
	for i in nums:
		y=i*i
	return y

What is happening here is it's counting how many numbers are in the list and then squaring it.I want the square of each number in the list....please help!thanks!

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  • Latest Post Latest Post by TrustyTony

Dani AI

Generated

's function is overwriting a single variable on each loop and then returning that one value, so you only get the final square instead of a list of squares. and pointed toward building a sequence; below are two alternative patterns that avoid using append and show different trade-offs.

If you want to modify the original list in place (no extra list allocation):

def square_each_inplace(nums):
    for i in range(len(nums)):
        nums[i] = nums[i] * nums[i]
    return nums

This is O(n) time and uses no extra list memory, but it mutates the input list — use it only when that side effect is acceptable.

If you prefer to produce a new list without append, use map (wrap with list() for Python 3):

def square_each_map(nums):
    return list(map(lambda x: x * x, nums))

map returns a list in Python 2 but an iterator in Python 3, so list(...) makes the function behave the same across versions. This keeps the original list unchanged and is concise.

Final notes: decide whether mutation is OK (in-place) or not (return new list). Validate input if there might be non-numeric items, and remember that the core bug in the original post was returning a single scalar rather than accumulating results — moving from “overwrite one variable” to “build or update a sequence” fixes it.

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All 6 Replies

Member Avatar for TrustyTony 
def squareEach(nums):
    return [i*i for i in nums]
Member Avatar for abcdr

Thanks!:) But what if it's in the arrangement like mine, how would you write that with the same output as yours?

Member Avatar for TrustyTony

Something like:

def squareEach(nums):
    squares=[]
    for number in nums:
        squares.append(number*number)
    return squares
Member Avatar for abcdr

what if <list>.append(x) is not used, is there any other way to write this code in that arrangement? I'm sorry...I'm new to this and I haven't learned that yet..well now i have but I can't use that yet. thanks!

Member Avatar for Beat_Slayer 
def squareEach(nums):
    squares=[]
    for number in nums:
        squares += [number * number]
    return squares
Member Avatar for TrustyTony

what if <list>.append(x) is not used, is there any other way to write this code in that arrangement? I'm sorry...I'm new to this and I haven't learned that yet..well now i have but I can't use that yet. thanks!

You could print them out instead of returning the value or build the result with +, which is not the recommended way. Or you could use recursion.

def squareEach(nums):
    squares=[]
    for number in nums:
        squares+=[number*number]
    return squares

# test it
print zip(range(20),squareEach(range(20)))
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