Python请求头我可以使用2d字典吗？

headers = {
    'User-Agent': 'Mozilla/5.0',
    'Accept-Language': 'en-US',
    'Content-Type': 'application/json',
    'Custom-Header': {
        'Key1': 'Value1',
        'Key2': 'Value2'
    }
}

# 获取请求头的值
user_agent = headers['User-Agent']
custom_header_value = headers['Custom-Header']['Key1']

# 修改请求头的值
headers['User-Agent'] = 'New User Agent'
headers['Custom-Header']['Key1'] = 'New Value1'

# 添加新的请求头
headers['New-Header'] = 'Value'

# 删除请求头
del headers['Content-Type']