Moved 1 to 5 to Python and learned a ton.

python/e003.py

@@ -0,0 +1,9 @@
+from lib_prime import prime_factors
+
+
+def euler_003():
+    return prime_factors(600851475143)[-1]
+
+
+assert(euler_003() == 6857)
+print("e003.py: {}".format(euler_003()))