translation: Add Python and Java code for EN version (#1345)

* Add the intial translation of code of all the languages

* test

* revert

* Remove

* Add Python and Java code for EN version

en/codes/python/chapter_tree/binary_tree_dfs.py

@@ -0,0 +1,65 @@
+"""
+File: binary_tree_dfs.py
+Created Time: 2022-12-20
+Author: a16su (lpluls001@gmail.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import TreeNode, list_to_tree, print_tree
+
+
+def pre_order(root: TreeNode | None):
+    """Pre-order traversal"""
+    if root is None:
+        return
+    # Visit priority: root node -> left subtree -> right subtree
+    res.append(root.val)
+    pre_order(root=root.left)
+    pre_order(root=root.right)
+
+
+def in_order(root: TreeNode | None):
+    """In-order traversal"""
+    if root is None:
+        return
+    # Visit priority: left subtree -> root node -> right subtree
+    in_order(root=root.left)
+    res.append(root.val)
+    in_order(root=root.right)
+
+
+def post_order(root: TreeNode | None):
+    """Post-order traversal"""
+    if root is None:
+        return
+    # Visit priority: left subtree -> right subtree -> root node
+    post_order(root=root.left)
+    post_order(root=root.right)
+    res.append(root.val)
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    # Initialize binary tree
+    # Use a specific function to convert an array into a binary tree
+    root = list_to_tree(arr=[1, 2, 3, 4, 5, 6, 7])
+    print("\nInitialize binary tree\n")
+    print_tree(root)
+
+    # Pre-order traversal
+    res = []
+    pre_order(root)
+    print("\nPrint sequence of nodes from pre-order traversal = ", res)
+
+    # In-order traversal
+    res.clear()
+    in_order(root)
+    print("\nPrint sequence of nodes from in-order traversal = ", res)
+
+    # Post-order traversal
+    res.clear()
+    post_order(root)
+    print("\nPrint sequence of nodes from post-order traversal = ", res)