<doocs>0226.Invert Binary Tree_1.py
def dfs(root):
    if root is None:
        return
    root.left, root.right = root.right, root.left
    dfs(root.left)
    dfs(root.right)
def sample_funcname ( var_1 ) :
    if var_1 is None :
        return
    var_1.left , var_1.right = var_1.right , var_1.left
    var_0 ( var_1.left )
    var_0 ( var_1.right )
