Rearrange the chapters.

Start to translate codes from Java to Python.

codes/python/include/print_util.py

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+'''
+File: print_util.py
+Created Time: 2021-12-11
+Author: Krahets (krahets@163.com)
+'''
+
+from .binary_tree import TreeNode, tree_to_list
+from .linked_list import ListNode, linked_list_to_list
+
+def print_matrix(mat):
+    """Print a matrix
+
+    Args:
+        mat ([type]): [description]
+    """    
+    pstr = []
+    for arr in mat:
+        pstr.append('  ' + str(arr))
+
+    print('[\n' + ',\n'.join(pstr) + '\n]')
+
+def print_linked_list(head):
+    """Print a linked list
+
+    Args:
+        head ([type]): [description]
+    """    
+    arr = linked_list_to_list(head)
+    print(' -> '.join([str(a) for a in arr]))
+
+
+class Trunk:
+    def __init__(self, prev=None, str=None):
+        self.prev = prev
+        self.str = str
+ 
+def showTrunks(p):
+    if p is None:
+        return
+    showTrunks(p.prev)
+    print(p.str, end='')
+ 
+def print_tree(root, prev=None, isLeft=False):
+    """Print a binary tree
+       This tree printer is borrowed from TECHIE DELIGHT
+       https://www.techiedelight.com/c-program-print-binary-tree/
+    Args:
+        root ([type]): [description]
+        prev ([type], optional): [description]. Defaults to None.
+        isLeft (bool, optional): [description]. Defaults to False.
+    """
+    if root is None:
+        return
+ 
+    prev_str = '    '
+    trunk = Trunk(prev, prev_str)
+    print_tree(root.right, trunk, True)
+ 
+    if prev is None:
+        trunk.str = '———'
+    elif isLeft:
+        trunk.str = '/———'
+        prev_str = '   |'
+    else:
+        trunk.str = '\———'
+        prev.str = prev_str
+ 
+    showTrunks(trunk)
+    print(' ' + str(root.val))
+    if prev:
+        prev.str = prev_str
+    trunk.str = '   |'
+    print_tree(root.left, trunk, False)