refractor: make function work for big numbers too

src/codewars/kata_doubly_not_less.py

@@ -1,9 +1,11 @@
 def doubly_not_less(n):
-    n_int = m = int(n)
-    m_condition = int("".join([str(x) for x in [int(x) for x in n][::-1]]))
+    n_int = int(n)
 
-    while m_condition < n_int:
-        m += 1
-        m_condition = int("".join([x for x in str(m)][::-1]))
+    # function reverses the order of a string of numbers to int
+    reverse = lambda x: int("".join([str(item) for item in [int(x) for x in x][::-1]]))
 
-    return str(m)
+    if reverse(n) >= n_int:
+        return n
+    return None
+
+print(doubly_not_less("23456"))