CODEWITHSUNDEEP
pythonlisttreenested
Eakc
Eakc

Reputation: 69

How To Convert A List to A Tree in Python?

How i can represent a tree from a nested list?

L = [['bike', '2 * wheel+1* frame'], ['wheel', '1*rim+1*spoke+1*hub'], ['rim', 60],['spoke', 120]

Tree = ['bike', 2, ['wheel', 1, ['rim', 60], 1, ['spoke', 120], 1, ['hub', 2]]

Explanation :

In this example bike is made from 2 wheels and 1 frames, wheel is made from 1 rim,1spoke and 1 hub ['rim', 60] means that rim's price is 60.

I could not understand how to convert the list to tree.

Upvotes: 0

Views: 2304

Answers (1)

Eric
Eric

Reputation: 97565

Here're the steps I'd take:

  1. Write a function such that f('2 * wheel+1* frame') == {'wheel': 2, 'frame': 1}

  2. Run that function on the entire list to generate

    [
    ('bike', {'wheel': 2, 'frame': 1}),
    ('wheel', {'rim': 1, 'spoke': 1, 'hub': 1}),
    ('rim', 60)
]

  3. Iterate over this list, and change it to:

    [
    ('bike', {
        ('wheel', {
            ('rim', 60): 1,
            ('spoke', ...): 1,
            ('hub', ...): 1
        }): 2,
        ('frame', ...): 1
    })            
]

    By replacing 'wheel' with ('wheel', {'rim': 1, 'spoke': 1, 'hub': 1}) etc, recursively

  4. Munge this tree format into the desired output

Upvotes: 2

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