try yourself |run program

mylist = [100,200,300,400,500]
newlist = []
for item in mylist:
    if item > 200:
        newlist.append(item)
    else:
        newlist.append(1000)
    
print(newlist)

# create a new list using comprehension
mylist = [100,200,300,400,500]
newlist = [item if item > 200 else 1000 for item in mylist]
print(newlist)

Program Output

[1000, 1000, 300, 400, 500]
[1000, 1000, 300, 400, 500]