the implementation of "child = childP1 + childP2" is wrong here. If we use the example in the figure of "Illustration of ordered crossover (credit: Lee Jacobson)", the resulting offspring of your implementation is "954321678" which is wrong. The correct result should be "954326781".

The original JAVA implementation by Lee Jacobson is correct. See the "public static Tour crossover(Tour parent1, Tour parent2)" in the GA.java of the original post. Look at how it loops through parent2's city tour.

Just for reference, I put my modified breed(parent1, parent2) function below:

child = [None] * len(parent1)
childP1 = []

geneA = int(random.random() * len(parent1))
geneB = int(random.random() * len(parent1))

startGene = min(geneA, geneB)
endGene = max(geneA, geneB)

for i in range(startGene, endGene):
    childP1.append(parent1[i])
    child[i] = parent1[i]  # copy segment to the same position

ptr = 0
for item in parent2:
    if item not in childP1:
        while ptr < len(parent1) and child[ptr] != None: # find the next None element
            ptr += 1

        child[ptr] = item  # only copy the remaining gene to positions that are None
        ptr += 1

return child

Hi I wish to know how can we plot a graph of route of path of cities generated in the end.