input: Write a python function to generate a random 8 character password that contains at least 1 uppercase letter, 1 lowercase letter, and 1 number.
  assert len(generate_password()) == 8
  assert any(c.isupper() for c in generate_password())
  assert any(c.islower() for c in generate_password())
  assert any(c.isdigit() for c in generate_password())
output: import random
  import string
  
  def generate_password():
      password = []
      password.append(random.choice(string.ascii_uppercase))
      password.append(random.choice(string.ascii_lowercase))
      password.append(random.choice(string.digits))
      while len(password) < 8:
          password.append(random.choice(string.ascii_letters + string.digits))
      random.shuffle(password)
      return ''.join(password)