0 1 1 2 3 5 in python

number1 = 0
print('1:', number1)
number2 = 1
for count in range(2, 101):
  print(count, ':', number1 + number2)
  number1 += number2
  number2 = number1 - number2

num = 1
num1 = 0
num2 = 1
import time
for i in range(0, 10):
    print(num)
    num = num1 + num2
    num1 = num2
    num2 = num
    time.sleep(1)

def fib(n, a=0, b=1): 
    '''fib(n) -> int
    returns the nth Fibonacci number
    '''
    if (n == 0): 
        return a
    return fib(n - 1, b, a + b)