3 kinds of realization of the sequence of Fibonacci-Tangent series

The Fibonacci number , also known as the Fibonacci sequence (Italian: Successione di Fibonacci), also known as the Golden Division Series, Fibonacci, Fibonacci, Fisher series, refers to such a series: 0, 1, 1, 2, 3, 5, 8, 13, 21st...... In mathematics, the Fibonacci sequence is defined as the following recursive method: F0=0,f1=1,fn=fn-1+fn-2 (n>=2,n∈n*), in words, is the Fibonacci sequence column starting with 0 and 1, after which the Fibonacci sequence coefficients are added by the previous two numbers.

1, implemented in a recursive way, with low efficiency

in [/]: def fib (n):
..: If n = 0:
...: return 0
..: If n ==1:
...: Return 1
..: Else:
...: return fib (n-1) + fib (n-2)
...:

in [+]: fib (5)
OUT[26]: 5


in [+]: fib (10)
OUT[27]: 55

2, by means of a for loop

in [[]: Def fib (n):
..: A,b = 0,1
...: For I in range (n):
..: A,b = b,a+b
..: Return a

in [[]: Def fib (n):
..: A,b = 0,1
..: LST = []
...: For I in range (n):
..: Lst.append (a)
..: A,b = b,a+b
...: Return LST

3, through the generator of the way to achieve

In [7]: def fib (n):
..: A,b = 0,1
...: For I in range (n):
..: Yield A
..: A,b = b,a+b

In [9]: for x in Fib (10):
..: Print (x)
...:
0
1
1
2
3
5
8
13
21st
34