Try to fix ruff

Author: MaximSmolskiy

Diff for: machine_learning/lstm/lstm_prediction.py

@@ -17,11 +17,11 @@
     make sure you set the price column on line number 21.  Here we
     use a dataset which have the price on 3rd column.
     """
-    df = pd.read_csv("sample_data.csv", header=None)
-    len_data = df.shape[:1][0]
+    sample_data = pd.read_csv("sample_data.csv", header=None)
+    len_data = sample_data.shape[:1][0]
     # If you're using some other dataset input the target column
-    actual_data = df.iloc[:, 1:2]
-    actual_data = actual_data.values.reshape(len_data, 1)
+    actual_data = sample_data.iloc[:, 1:2]
+    actual_data = actual_data.to_numpy().reshape(len_data, 1)
     actual_data = MinMaxScaler().fit_transform(actual_data)
     look_back = 10
     forward_days = 5