What am I missing here?

4.4.1:While loop: Print 1 to N.

Use a while loop that prints from 1 to user_num, increasing by 1 each time.

Sample output with input: 4

1 2 3 4 

my code is :

i = 1

user_num = int(input()) # Assume positive

while i == user_num:

i =+ 4

print(i,' ')