python - Django:递归获取模型字段(外键及其字段)作为字符串进入 1 级列表

Question

我在 Django 中构建一个项目，需要将给定模型中的所有字段列为 html 选择标记的选项。我写了一个递归函数来读取模型并返回一个包含所有字段和子字段的列表。像这样:

def get_fields_true_hierarchy(model, list_fields = []):
    fields_obj = model._meta.fields
    for field_obj in fields_obj:
        if field_obj.rel:
            dict_fields = {field_obj.attname: []}
            list_fields.append(dict_fields)
            get_fields_true_hierarchy(field_obj.rel.to, dict_fields[field_obj.attname])
        else:
            list_fields.append(field_obj.attname)
    return list_fields

它返回如下对象:

fiedls = [
    'id', 
    'title', 
    'number', 
    'start_date', 
    'finish_date', 
    {'status_id':
        ['id', 
        'name']
    }, 
    'postal_code', 
    {'requestor_id': 
        ['id', 
        {'user_id': 
            ['id', 
            'password', 
            'last_login', 
            'is_superuser', 
            'username', 
            'first_name', 
            'last_name', 
            'email', 
            'is_staff', 
            'is_active', '
            date_joined']
        }, 
        'name', 
        'phone', 
        'email',  
        'contact_name', 
        'contact_email']
    }, 
    {'reason_id': 
        ['id', 
        'description']
    }, 
    'details', 
    {'group_id': 
        ['id', 
        'description']
    }, 
    {'subgroup_id': 
        ['id', 
        'description']
    }, 
    {'manager_id': 
        ['id', 
        'password', 
        'last_login', 
        'is_superuser', 
        'username', 
        'first_name', 
        'last_name', 
        'email', 
        'is_staff', 
        'is_active', 
        'date_joined']
    }, 
    'datetime_subscription', 
    'allowed', 
    'data_def'
]

但是，我需要得到一个单层列表，如下所示:

fiedls = [
    'id', 
    'title', 
    'number', 
    'start_date', 
    'finish_date', 
    'status_id',
    'status_id.id', 
    'status_id.name', 
    'postal_code', 
    'requestor_id',
    'requestor_id.id', 
    'requestor_id.user_id',
    'requestor_id.user_id.id', 
    'requestor_id.user_id.password', 
    'requestor_id.user_id.last_login', 
    'requestor_id.user_id.is_superuser',
    'requestor_id.user_id.username', 
    'requestor_id.user_id.first_name', 
    'requestor_id.user_id.last_name', 
    'requestor_id.user_id.email', 
    'requestor_id.user_id.is_staff', 
    'requestor_id.user_id.is_active',
    'requestor_id.user_id.date_joined',
    'requestor_id.name', 
    'requestor_id.phone', 
    'requestor_id.email',  
    'requestor_id.contact_name', 
    'requestor_id.contact_email',
    'reason_id',
    'reason_id.id', 
    'reason_id.description',
    'details',
    'group_id', 
    'group_id.id', 
    'group_id.description',
    'subgroup_id',
    'subgroup_id.id', 
    'subgroup_id.description',
    'manager_id', 
    'manager_id.id',
    'manager_id.password', 
    'manager_id.last_login', 
    'manager_id.is_superuser', 
    'manager_id.username', 
    'manager_id.first_name', 
    'manager_id.last_name', 
    'manager_id.email', 
    'manager_id.is_staff', 
    'manager_id.is_active', 
    'manager_id.date_joined',
    'datetime_subscription', 
    'allowed',
    'data_def'
]

我无法编写递归函数来返回这样的结果。您对如何执行此任务有任何想法吗？我被困在下面的这个功能上。但它的行为并不像预期的那样。

PS.: list_fields 参数将来自 get_fields_true_hierarchy() 函数。

def get_fields_fake_hierarchy(list_fields, fake_hierarchy = [], parent_str = "", reset=True):
    for field in list_fields:
        if reset:
            parent_str = ""
        if isinstance(field, dict):
            for key, value in field.iteritems():
                fake_hierarchy.append(key)
                parent_str += "."+key
                get_fields_fake_hierarchy(value, fake_hierarchy, parent_str, reset=False)
        else:
            fake_hierarchy.append("%s.%s"%(parent_str, field))
    fake_hierarchy = [i[1:] if i[0]=='.' else i for i in fake_hierarchy]
    return fake_hierarchy

Answer 1

改用递归生成器，并动态地为名称添加前缀:

def do_prefix(name, prefix):
    if prefix:
        return "%s.%s" % (prefix, name)
    return name

def get_fields_flat(model):
    return [name for name in iter_fields(model)]

def iter_fields(model, prefix=None):
    fields = model._meta.fields
    for field in fields:
        name = do_prefix(field.attname, prefix)
        yield  name
        if field.rel:
            rel = field.rel.to
            for f in iter_fields(rel, name):
                yield f