Fixed infinite loop issue in "euclidean_example.py" (#749)

* Fixed infinite loop issue in "euclidean_example.py"

* Changed line numbers in "euclidean_algorithm.md" for python

Author: valdaarhun

contents/euclidean_algorithm/code/python/euclidean_example.py

@@ -13,6 +13,11 @@ def euclid_sub(a, b):
     a = abs(a)
     b = abs(b)
 
+    if a == 0:
+        return b
+    elif b == 0:
+        return a
+
     while a != b:
         if a > b:
             a -= b

contents/euclidean_algorithm/euclidean_algorithm.md

@@ -24,7 +24,7 @@ The algorithm is a simple way to find the *greatest common divisor* (GCD) of two
 {% sample lang="lisp" %}
 [import:3-12, lang="lisp"](code/clisp/euclidean.lisp)
 {% sample lang="py" %}
-[import:11-22, lang="python"](code/python/euclidean_example.py)
+[import:11-27, lang="python"](code/python/euclidean_example.py)
 {% sample lang="hs" %}
 [import:3-13, lang="haskell"](code/haskell/euclidean_algorithm.hs)
 {% sample lang="rs" %}