Code Explaination

[Mehreen]

hi can someone briefly explain me whats happening in the code below?

input_symptoms=('polyuria','polydypsia','pain chest','shortness of breath')
from simpleai.search import CspProblem, backtrack
def constraint(variables,values):
    for i in range(len(values)-1):
        if values[i]!=values[i+1]:
            return False
    return True

if __name__=='__main__':
    constraints=[(input_Symptom_list,constraint)]
    problem=CspProblem(input_Symptom_list,Symptom_Disease,constraints)
    output = backtrack(problem)
    for k,v in output.items():
        print(k, '==>',v)