Python Numbers Guessing Game

I'm a beginner programmer learning Python (using version 2.7.4) and I've made this number guessing game. Here's my code so far for it:

import random
name = raw_input("Hi there! What\'s your name?\n")
print "Well, " + name + ", I am thinking of a number between 1 and 100"
number = random.randint(1,100)
guess = int(raw_input("Take a guess:\n"))


count = 1

while guess != number:    
    if guess < number:
        print "Sorry, your guess is too low."                 
    if guess > number:
        print "Sorry, your guess is too high."
    count += 1
    guess = int(raw_input("Take another guess\n"))

print "Good job, %s! You guessed my number in %d guesses!" % (name ,count)

1. How do I alert the player of a guess that they've already previously guessed before?
2. How do I make sure that the player can only input numbers as their guess? I'm stumped. Thanks!