Amazing-Python-Scripts

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"""
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GENERAL TREE
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    Data is stored in hierarchical form
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                                            ROOT                                            --- Level 0
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                         ____________________|____________________
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                         A                   B                   C                          --- Level 1
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                    _____|_____         _____|_____         _____|_____
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                    |         |         |    |     |        |   |   |  |
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                    D         E         F    G     H        I   J   K  L                    --- Level 2
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               _____|_____              _____|_____
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               |   |  |  |              |         |
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               M   N  O   P             Q         R                                         --- Level 3
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         Here, ROOT is "ROOT NODE" and A, B, C are "CHILD NODE"
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            > B-D-F-G is a sub-tree
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            > B is 'ROOT NODE' for F, G, H and G is 'ROOT NODE' for Q, R
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            > Those nodes [E, F, H, I, J, K, L...] who do not have any child node are "LEAF NODE"
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            > For (D, E), A will be Ancestor and for A, (D, E) would be Descendants
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    Tree is a recursive dta structure where a child node is another tree in itself
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"""
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class TreeNode:
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    """ Class TreeNode """
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    def __init__(self, data):
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        self.data = data
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        self.children = []
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        self.parent = None
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    def add_child(self, child):
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        """ Adds children elements to Tree """
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        child.parent = self  # child is an instance of class(node)
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        # adding a child node to tree
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        self.children.append(child)
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    def get_level(self):
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        """ Gets the level of Tree by counting ancestors: if a node has no ancestor, it is root node """
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        level = 0  # initialised level to 0
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        p = self.parent
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        while p:
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            """keep on going through parents and increasing levels"""
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            level += 1  # increase level by 1
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            p = p.parent
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        return level
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    def print_tree(self):
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        """Display Tree in hierarchical format"""
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        spaces = ' ' * self.get_level() * 3  # printing 3 spaces for each level
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        prefix = spaces + "|__" if self.parent else ""
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        # prints prefix(probably spaces) based on level
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        print(prefix + self.data)
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        # At leaf nodes, self.children will be an empty array... so we create a check if self.children() is an empty array or not
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        if self.children:  # checks if len(self.children > 0)
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            for child in self.children:
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                child.print_tree()  # It will recursively call this fn and print the sub-trees
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def electronic_product():
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    root = TreeNode("Electronics")
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    laptop = TreeNode("Laptop")
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    laptop.add_child(TreeNode("Mac"))
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    laptop.add_child(TreeNode("Surface"))
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    laptop.add_child(TreeNode("Thinkpad"))
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    cellphones = TreeNode("cell Phone")
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    cellphones.add_child(TreeNode("iphone"))
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    cellphones.add_child(TreeNode("Samsung"))
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    cellphones.add_child(TreeNode("Vivo"))
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    tv = TreeNode("TV")
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    tv.add_child(TreeNode("Samsung"))
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    tv.add_child(TreeNode("MI"))
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    root.add_child(laptop)
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    root.add_child(cellphones)
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    root.add_child(tv)
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    # print(laptop.get_level()) # 1
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    # print(cellphones.get_level()) # 1
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    # print(tv.get_level()) # 1
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    return root
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# main method
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if __name__ == '__main__':
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    root = electronic_product()
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    root.print_tree()  # prints tree in hierarchical format
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    # print(root.get_level()) # 0 // get level of root node
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