How to enter only 4 digit no. in python

Question

if you will enter more and less it will show error

Answer 1

After getting input as int

n > 9999 or n < 1000

:x

or maybe just

len(str(n)) != 4

Answer 2

You could also do it in one compare:
if 1000 <= x < 10000:
# do stuff

Answer 3

Here's one way to do it

while True:
try:
n = int(input('4-digit number: '))
if n in range(1000, 10000):
break
except:
pass