python - 我的解决方案和算法有什么问题

Question

返回 num_dict 中具有以下特征的所有键(作为一组)值大于或等于 min_cutoff。

参数:

• num_dict:字典。 num_dict 中的所有值都是数字。
• min_cutoff: float 。与 num_dict 值进行比较。返回所有键，其中它们的值 >= min_cutoff。
• set:num_dict 中值符合截止标准的所有键。

示例:

keys_geq_cutoff({'Alice': 21, 'Brett': 20, 'Carlos': 31}, 21)
{'Alice', 'Carlos'}

我的代码:

def keys_geq_cutoff(num_dict, min_cutoff):
    for k, v in num_dict.items():
        if (v >= min_cutoff):
            return(keys_geq_cutoff(num_dict, min_cutoff))

错误:

test_keys_geq_cutoff (test_methods.TestPython1)
Traceback (most recent call last):
  File "/usr/src/app/test_methods.py", line 13, in test_keys_geq_cutoff
    result1 = main.keys_geq_cutoff(test_d, 0)
  File "/usr/src/app/main.py", line 4, in keys_geq_cutoff
    return(keys_geq_cutoff(num_dict, min_cutoff))
  File "/usr/src/app/main.py", line 4, in keys_geq_cutoff
    return(keys_geq_cutoff(num_dict, min_cutoff))
  File "/usr/src/app/main.py", line 4, in keys_geq_cutoff
    return(keys_geq_cutoff(num_dict, min_cutoff))
  [Previous line repeated 956 more times]
  File "/usr/src/app/main.py", line 3, in keys_geq_cutoff
    if (v >= min_cutoff):
RecursionError: maximum recursion depth exceeded in comparison

Answer 1

现在，您正在 return 语句中使用完全相同的参数再次调用该函数，因此会出现 RecursionError。您需要收集一组内的 key ，然后返回该组:

def keys_geq_cutoff(num_dict, min_cutoff):
    res = set()
    for k, v in num_dict.items():
        if (v >= min_cutoff):
            res.add(k)
    return res

或者，可以使用一个很好的集合理解:

def keys_geq_cutoff(num_dict, min_cutoff):
    return {k for k, v in num_dict.items() if v >= min_cutoff}