Refactor code for improved readability and consistency across multiple Jupyter notebooks

- Added missing commas in various print statements and function calls for better syntax.
- Reformatted code to enhance clarity, including breaking long lines and aligning parameters.
- Updated function signatures to use float type for sigma parameters instead of int for better precision.
- Cleaned up comments and documentation strings for clarity and consistency.
- Ensured consistent formatting in plotting functions and data handling.

M1/Statistical Learning/TP0_Intro_Jupyter_Python.ipynb

@@ -1114,7 +1114,12 @@
     "R = multivariate_normal([0, 0], np.eye(2))\n",
     "\n",
     "surf = ax.plot_surface(\n",
-    "    X, Y, R.pdf(np.dstack((X, Y))), cmap=\"coolwarm\", linewidth=0, antialiased=False\n",
+    "    X,\n",
+    "    Y,\n",
+    "    R.pdf(np.dstack((X, Y))),\n",
+    "    cmap=\"coolwarm\",\n",
+    "    linewidth=0,\n",
+    "    antialiased=False,\n",
     ")\n",
     "\n",
     "fig.colorbar(surf, shrink=0.5, aspect=5)\n",