input: Write a function to generate a random password by using a predefined set of letters, numbers, and special characters. The function should randomly select characters from the given set and form a password of the specified length.
  
  
  import random
  
  def generate_password(length=8):
      string = "abcdefghijklmnopqrstuvwxyz01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()?"
      password = "".join(random.sample(string, length))
      return password
  
  assert generate_password()=="".join(random.sample("abcdefghijklmnopqrstuvwxyz01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()?", 8))
  
output: def generate_password(length=8):
      string = "abcdefghijklmnopqrstuvwxyz01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()?"
      password = "".join(random.sample(string, length))
      return password