Find all tuples related to a certain string in Python

Question

I am trying to find all tuples related to a string, not just matched to it. Here is what I made:

from itertools import chain

data = [(\'A\',\'B\'),(\'B\',\'         


        

Answer 1

A very naive solution, might not be efficient for complicated trees.

data = [('A', 'B'), ('B', 'C'), ('B', 'D'), ('B', 'F'),
        ('F', 'W'), ('W', 'H'), ('G', 'Z')]
init = ['A']
result = []
while init:
    initNEW = init.copy()
    init = []
    new = 0
    for edge in data:
        for vertex in initNEW:
            if edge[0] == vertex:
                result.append(edge)
                init.append(edge[1])
                new += 1
    for i in range(len(result) - new, len(result)):
        data.remove(result[i])
print(result)
# [('A', 'B'), ('B', 'C'), ('B', 'D'), ('B', 'F'), ('F', 'W'), ('W', 'H')]