update assignment D Recursion

D_recursion/README.md

@@ -119,21 +119,23 @@ and each following number is the sum of the two preceding numbers.
 
 Fibonacci numbers are widely found in *nature*, *science*, *social behaviors* of
 populations and *arts*, e.g. they form the basis of the
-[Golden Ratio](https://www.adobe.com/creativecloud/design/discover/golden-ratio.html)
-in *painting* and *photography*, see also this
+[Golden Ratio](https://www.adobe.com/creativecloud/design/discover/golden-ratio.html),
+which is widely used in *painting* and *photography*, see also this
 [1:32min](https://www.youtube.com/watch?v=v6PTrc0z4w4) video.
 
-<img src="../markup/img/fibonacci.jpg" alt="drawing" width="600"/>
+<img src="../markup/img/fibonacci.jpg" alt="drawing" width="640"/>
 <!-- ![image](../markup/img/fibonacci.jpg) -->
 
-Complete functions `fib(n)` and `fig_gen(n)`.
+&nbsp;
+
+Complete functions `fib(n)` and `fib_gen(n)`.
 
 ```py
 def fib(self, _n) -> int:
     # return value of n-th Fibonacci number
     return #...
 
-def fib_seq(self, _n):
+def fib_gen(self, _n):
     # return a generator object that yields two lists, one with n and the
     # other with corresponding fib(n)
     yield #...

D_recursion/recursion.py

@@ -30,7 +30,7 @@ class Recursion:
         return 0
 
 
-    def fib_seq(self, _n):
+    def fib_gen(self, _n):
         """
         Return a generator object that yields two lists, one with n and the
         other with corresponding fib(n).
@@ -152,7 +152,7 @@ if __name__ == '__main__':
 
     # Challenge 2.1, fig_gen()
     if 21 in run_choices:
-        gen = n1.fib_seq(20)    # yield generator object
+        gen = n1.fib_gen(20)    # yield generator object
         n, fib = next(gen)      # trigger generator
         print(f'n:      {n}')
         print(f'fib(n): {fib}')