Moved problems till 56 to Python.

python/e051.py

@@ -1,8 +1,38 @@
+from itertools import combinations
+from lib_prime import primes
+
+
+def get_replacements(n):
+    n = str(n)
+    xss = [[i for i in range(0, len(n)) if n[i] == d]
+           for d in "0123456789"]
+    xss = [x
+           for xs in xss if xs
+           for i in range(1, len(xs) + 1)
+           for x in combinations(xs, i)]
+    xss = ["".join(['x' if i in xs else d for i, d in enumerate(n)])
+           for xs in xss]
+    return xss
+
 
 def euler_051():
-    return 0
+    replacements = {}
+    ps = primes(1000000)
+    for p in ps:
+        for r in get_replacements(p):
+            try:
+                replacements[r].append(p)
+                if len(replacements[r]) == 8:
+                    # print(replacements[r])
+                    s = replacements[r][0]
+                    return s
+            except KeyError:
+                replacements[r] = [p]
+        if p > 1000000:
+            break
+    return s
 
 
 if __name__ == "__main__":
     print("e051.py: " + str(euler_051()))
-    assert(euler_051() == 0)
+    assert(euler_051() == 121313)