Add typing annotations to Python codes. (#411)

codes/python/modules/print_util.py

@@ -4,57 +4,48 @@ Created Time: 2021-12-11
 Author: Krahets (krahets@163.com), msk397 (machangxinq@gmail.com)
 """
 
-from .binary_tree import TreeNode, tree_to_list, list_to_tree
+from .binary_tree import TreeNode, list_to_tree
 from .linked_list import ListNode, linked_list_to_list
 
-def print_matrix(mat):
-    """Print a matrix
+from typing import List, Optional, Dict
 
-    Args:
-        mat ([type]): [description]
-    """    
-    pstr = []
+def print_matrix(mat: List[List[int]]) -> None:
+    """ Print a matrix """    
+    s: List[str] = []
     for arr in mat:
-        pstr.append('  ' + str(arr))
+        s.append('  ' + str(arr))
 
-    print('[\n' + ',\n'.join(pstr) + '\n]')
+    print('[\n' + ',\n'.join(s) + '\n]')
 
-def print_linked_list(head):
-    """Print a linked list
-
-    Args:
-        head ([type]): [description]
-    """    
-    arr = linked_list_to_list(head)
+def print_linked_list(head: Optional[ListNode]) -> None:
+    """ Print a linked list """    
+    arr: List[int] = 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 show_trunks(p):
+    def __init__(self, prev: Optional['Trunk'] = None, string: Optional[str] = None) -> None:
+        self.prev: Optional[Trunk] = prev
+        self.str: Optional[str] = string
+
+def show_trunks(p: Optional[Trunk]) -> None:
     if p is None:
         return
     show_trunks(p.prev)
     print(p.str, end='')
- 
-def print_tree(root, prev=None, is_left=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.
-        is_left (bool, optional): [description]. Defaults to False.
+
+def print_tree(root: Optional[TreeNode], prev: Optional[Trunk] = None, is_left: bool = False) -> None:
+    """
+    Print a binary tree
+    This tree printer is borrowed from TECHIE DELIGHT
+    https://www.techiedelight.com/c-program-print-binary-tree/
     """
     if root is None:
         return
- 
-    prev_str = '    '
+
+    prev_str: str = '    '
     trunk = Trunk(prev, prev_str)
     print_tree(root.right, trunk, True)
- 
+
     if prev is None:
         trunk.str = '———'
     elif is_left:
@@ -63,7 +54,7 @@ def print_tree(root, prev=None, is_left=False):
     else:
         trunk.str = '\———'
         prev.str = prev_str
- 
+
     show_trunks(trunk)
     print(' ' + str(root.val))
     if prev:
@@ -71,17 +62,14 @@ def print_tree(root, prev=None, is_left=False):
     trunk.str = '   |'
     print_tree(root.left, trunk, False)
 
-def print_dict(d):
-    """Print a dict
-
-    Args:
-        d ([type]): [description]
-    """
-    for key, value in d.items():
+def print_dict(mapp: Dict) -> None:
+    """ Print a dict """
+    for key, value in mapp.items():
         print(key, '->', value)
 
-def print_heap(heap):
-    print("堆的数组表示：", heap);
-    print("堆的树状表示：");
-    root = list_to_tree(heap)
-    print_tree(root);
+def print_heap(heap: List[int]) -> None:
+    """ Print a heap both in array and tree representations """  
+    print("堆的数组表示：", heap)
+    print("堆的树状表示：")
+    root: Optional[TreeNode] = list_to_tree(heap)
+    print_tree(root)