Adopted new convention from template

src/Python/Problems001-050/Problem025.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python
 """
 Created on 11 Sep 2019
 
@@ -17,7 +17,7 @@ def compute():
     """
     The Fibonacci sequence is defined by the recurrence relation:
 
-        Fn = Fn−1 + Fn−2, where F1 = 1 and F2 = 1.
+        Fn = Fn-1 + Fn-2, where F1 = 1 and F2 = 1.
 
     Hence the first 12 terms will be:
 
@@ -39,16 +39,15 @@ def compute():
     What is the index of the first term in the Fibonacci sequence to
     contain 1000 digits?
     """
-    a, b = 1, 1
-    index = 2
 
+    a, b = 1, 1
+    ans = 2
     while len(str(b)) < 1000:
         a, b = b, b + a
-        index += 1
+        ans += 1
 
-    return index
+    return ans
 
 
 if __name__ == "__main__":
-
-    print(f"Result for Problem 25: {compute()}")
+    print(f"Result for Problem 25 is {compute()}")