替換從dict中刪除空值，在python中遞歸列出

Question

我為刪除每個 Null 或空內容的任務編寫了以下代碼。 該腳本有效，但我認為它根本不是“pytonish”。 python 怎么做？

def remove_empty_values(ret):
    #ret is assumed eitehr dict or list
    #recursively remove all key or list items which values is Null or empty string
    if type(ret) == list:
            empty_indexes=[]
            i = 0
            for index in ret:
                    if (ret[i] == None) or ((type(ret[i]) == str and  ret[i] == '') or ((type(ret[i]) == unicode and  ret[i] == '') or (( type(ret[i])==dict or type(ret[i])==list )  and len(ret[i]) ==0))):
                            empty_indexes.append(i)
                    else:
                             if (type(ret[i])==dict or type(ret[i])==list):
                                    remove_empty_values(ret[i])
                    i = i + 1
            for index in empty_indexes:
                    del ret[index]

    elif type(ret) == dict:

            empty_keys=[]
            for key in ret:
                    if (ret[key] == None) or ((type(ret[key]) == str and ret[key] == '') or ((type(ret[key]) == unicode and ret[key] == '') or (( type(ret[key])==dict or type(ret[key])==list )  and len(ret[key]) ==0))):
                            empty_keys.append(key)
                    else:
                             if (type(ret[key])==dict or  type(ret[key])==list):
                                    remove_empty_values(ret[key])
            for key in empty_keys:
                    del ret[key]

Answer 1

如果您使用 Python 3.8+，則可以使用賦值表達式:= ：

例如：

d = {'a': [{'b': 'x', 'c': ''}], 'c': ['', '1', None], 'd': ['']}


def remove(i):
    if isinstance(i, dict):
        return {k: vv for k, v in i.items() if (vv:=remove(v))}
    elif isinstance(i, list):
        return [vv for v in i if (vv:=remove(v))]
    return i

print(remove(d))

印刷：

{'a': [{'b': 'x'}], 'c': ['1']}

---

編輯：保持零和False ：

d = {'a': [{'b': 'x', 'c': ''}], 'c': ['', '1', None], 'd': ['', 0, False]}


def remove(i):
    if isinstance(i, dict):
        return {k: vv for k, v in i.items() if (vv:=remove(v)) or v is False or v == 0}
    elif isinstance(i, list):
        return [vv for v in i if (vv:=remove(v)) or v is False or v == 0]
    return i

print(remove(d))

印刷：

{'a': [{'b': 'x'}], 'c': ['1'], 'd': [0, False]}