While True will keep going until the loop is stopped with "break". The "continue" command restarts the current loop level. Your code could look something like this:
import random
from random import randint
def randompick():
num = randint(0, 10)
while True:
if int(input("Pick a number you think is the random number between 1 and 10: ")) == num:
print("You have guessed the number")
break
else:
continue
randompick()
You can also use Try / Except to validate the input and make sure it's a number, and not a letter:
import random
from random import randint
def randompick():
num = randint(0, 10)
while True:
try:
guess = int(input("Pick a number you think is the random number between 1 and 10: "))
except:
print('Not a number, try again.')
continue
if int(guess) == num:
print("You have guessed the number")
break
else:
continue
randompick()