UP my solution

Author: Jean

numpy_questions.py

@@ -39,8 +39,12 @@ def max_index(X):
     """
     i = 0
     j = 0
-
-    # TODO
+    if not isinstance(X, np.ndarray):
+        raise ValueError("The input is not a numpy array")
+    if len(X.shape) != 2:
+        raise ValueError("The shape is not 2D")
+    max = np.argmax(X)
+    i, j = np.unravel_index(max, X.shape)
 
     return i, j
 
@@ -62,6 +66,11 @@ def wallis_product(n_terms):
     pi : float
         The approximation of order `n_terms` of pi using the Wallis product.
     """
-    # XXX : The n_terms is an int that corresponds to the number of
-    # terms in the product. For example 10000.
-    return 0.
+    prod = 1  # Initialisation du produit
+    if n_terms > 0:
+        for n in range(1, n_terms + 1):
+            term = (4 * n**2) / (4 * n**2 - 1)
+            prod *= term
+
+    # Multiplier par 2 pour obtenir l'approximation de pi
+    return 2 * prod