'NoneType'对象在python中没有属性'append'

Question

我在python中有以下函数:

def find_str(s, m):
    starting_points = find_starting_points(s,m)
    solution = []
    for i in range(0, len(starting_points)):
        position = starting_points[i]
        solution.append([position])
        solution = build_solution(position, s, m, solution)
    return solution
    pass

当我在ipython中运行该文件时,我收到以下错误:

     55     for i in range(0, len(starting_points)):
     56         position = starting_points[i]
---> 57         solution.append([position])
     58         solution = build_solution(position, s, m, solution)
     59     return solution

AttributeError: 'NoneType' object has no attribute 'append'

为什么我会收到这个错误？

Answer 1

你的build_solution功能在某些时候会回来None.由于您设置solution为返回此功能,因此您将其设置为无.

除非你显示代码,否则我不能更具体build_solution.