how to make sure an input is from the wanted type

[astral_travel]

i tried this:

import random

RNumber = random.randint(1,10)

try:
    user_input = int(input("please guess a number between 0 and 10: \n"))
except ValueError:
    print("you have typed an invalid input")

count = 1

while user_input != RNumber:
    try:
        if user_input > RNumber:
            user_input = int(input("choose a lower number: \n"))
        elif user_input < RNumber:
            user_input = int(input("choose a higher number: \n"))
    except ValueError:
        print("you have typed an invalid input")
    count += 1

print(f"the number you chose is correct {RNumber}\n")

print(f"you have guessed the right number in {count} times")

it works when in the first time i am asked to enter a number, and then after i choose some number - i type some string, it works okay,
but if right on the first time i'm prompted i enter a string - it gives the right output - but then also an error...
the output is this:

Output:
/home/tal/PycharmProjects/pythonProject1/venv/bin/python /home/tal/code/pycharm-community-2020.2.3/plugins/python-ce/helpers/pydev/pydevd.py --multiprocess --qt-support=auto --client 127.0.0.1 --port 42581 --file /home/tal/PycharmProjects/pythonProject2/experiment.py 
please guess a number between 0 and 10: 
you have typed an invalid input
Traceback (most recent call last):
  File "/home/tal/code/pycharm-community-2020.2.3/plugins/python-ce/helpers/pydev/pydevd.py", line 1496, in _exec
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "/home/tal/code/pycharm-community-2020.2.3/plugins/python-ce/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "/home/tal/PycharmProjects/pythonProject2/experiment.py", line 12, in <module>
    while user_input != RNumber:
NameError: name 'user_input' is not defined

Process finished with exit code 1

how come this is so ? is there a way to correct it ?