ajout fonctions de base pour parse des données et les analyser

poll.py

@@ -0,0 +1,10 @@
+def sample_every_kth_point(df, k):
+    # Validate the input to ensure k is positive and does not exceed the DataFrame length
+    if k <= 0:
+        raise ValueError("k must be a positive integer.")
+    if k > len(df):
+        raise ValueError("k is greater than the number of rows in the DataFrame.")
+
+    # Sample every k-th point
+    sampled_df = df.iloc[::k]
+    return sampled_df