刚开始学习 python； 当我使用列表推导时，为什么这个 for 循环的打印不同？ 我如何使循环相同？

Question

from my understanding shouldn't the print for X be the same on both? the answer i need is the one that comes from the list-comprehension, which is a new list where every element is -1 from the original list. But the for-loop one only gives 1 element, I also don't know how that element is calculated. Printing x just gives the last element of the list. I'm sure i'm doing something wrong but i'm not sure how to get a list from just using the for-loop. WHAT IS CONFUSING ME is that if the print(x) is part of the for loop it will print the elements of the desired list I need, but NOT in a list, which means the math I wrote works as intended, right?

list= [1,2,3,4,5]


#loop
x=[]
for i in list:
  x=[i-1]
print(x)

#list comprehension

x=[i-1 for i in list]
print(x)

#confusing part where this print will be the same as the comprehension but not in a list form
 x=[]
for i in list:
  x=[i-1]
  print(x)

Answer 1

First thing, list is a protected keyword. You should be using list_ at least (that's the naming convention if you really need to use list as the name).

The second iterates element by element, and prints each of the elements, what you want is in the loop to set each of the elements one by one, and then print x (not inside the loop).

list_= [1,2,3,4,5]

x=[]
for i in list_:
  x.append(i-1)
print(x)

Answer 2

You should append like this:

lst= [1,2,3,4,5]

#loop
x=[] 
for i in lst: 
    x.append(i-1)
print(x)
#output: [0, 1, 2, 3, 4]

#list comprehension
x=[i-1 for i in lst] 
print(x)
#output: [0, 1, 2, 3, 4]