Example of how Python implements the Fibonacci sequence

Introduced

The Fibonacci sequence, also known as the Golden Section, refers to a sequence of numbers 0, 1, 1, 2, 3, 5, 8, 13, and 、...... Mathematically, the Fibonacci sequence is defined in the following recursive way:

F (0) =0,f (1) =1,f (n) =f (n-1) +f (n-2) (n≥2,n∈n*).

1. Meta-Group implementation

Fibs = [0, 1]for I in range (8): Fibs.append (Fibs[-2] + fibs[-1])

This will give you a list of Fibonacci numbers within the specified range.

2. Iterator implementation

Class Fibs:def __init__ (self):  self.a = 0  self.b = 1  def next (self):  self.a, self.b = self.b, self.a + SE lf.b  return SELF.A  def __iter__ (self):  return to self

This will get an infinite number of columns that can be accessed in the following ways:

fibs = fibs () for F in Fibs:if F > £:  print F break  else:  print F

3. By customizing the class implementation

Class Fib (object): Def __getitem__ (self, n):  if Isinstance (n, Int.):   A, B = 1, 1 for   x in range (n):    A, B = b, a + b   return a  elif isinstance (n, slice):   start = N.start   stop = N.stop   A, b = 1, 1   L = []
  
   for x in range (stop):    if x >= start:     l.append (a)    A, B = B, a + b   return L  else:   raise Ty Peerror ("Fib indices must be integers")
  

This gives you a sequence-like data structure that can be used to access data by subscript:

f = Fib () print F[0:5]print f[:10]

4.Python implementation of the simpler Fibonacci sequence example

Let's start with a Fibonacci sequence and see ...

0 1 1 2 3 5 8 13 21 34 55 89 144 233 ...

The first two variables are assigned values:

I, j = 0, 1

Of course, you can also write this:

i = 0J = 1

Then set a range, just 10000 within the good:

While I < 10000:

Then output I in the while statement and design the logic:

Print I,i, j = j, I+j

It is important to note here: "I, j = i, i+j" This code cannot be written as follows:

i = JJ = I+j

If written like this, J is not the sum of the first two bits, but the sum of I and J that has been assigned by J, so the output sequence will look like this:

0 1 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192

The correct whole piece code is as follows:

I, j = 0, 1while i < 10000:print I, I, j = j, I+j

Finally show the results of the operation:

0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765

Summarize

The above is about the use of Python to achieve the Fibonacci sequence of all the content, I hope that the content of this article on everyone's study or work can bring certain help, if there are questions you can message exchange.