Python __init__() 缺少 1 个必需的位置参数
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/19929626/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
__init__() missing 1 required positional argument
提问by eddard.stark
I am trying to learn Python. This is a really simple code. All I am trying to do here is to call a class's constructor. Initialize some variables there and print that variable. But it is giving me an error. It is saying:
我正在尝试学习 Python。这是一个非常简单的代码。我在这里要做的就是调用类的构造函数。在那里初始化一些变量并打印该变量。但它给了我一个错误。它在说：
missing 1 required positional argument
缺少 1 个必需的位置参数
Here is my code:
这是我的代码：
class DHT:
def __init__(self, data):
self.data['one'] = '1'
self.data['two'] = '2'
self.data['three'] = '3'
def showData(self):
print(self.data)
if __name__ == '__main__': DHT().showData()
采纳答案by Mike
You're receiving this error because you did not pass a datavariable to the DHT constructor.
您收到此错误是因为您没有将data变量传递给 DHT 构造函数。
aIKid and Alexander's answers are nice but it wont work because you still have to initialize self.datain the class constructor like this:
aIKid 和 Alexander 的答案很好，但它不起作用，因为您仍然必须self.data在类构造函数中进行初始化，如下所示：
class DHT:
def __init__(self, data=None):
if data is None:
data = {}
else:
self.data = data
self.data['one'] = '1'
self.data['two'] = '2'
self.data['three'] = '3'
def showData(self):
print(self.data)
And then calling the method showData like this:
然后像这样调用 showData 方法：
DHT().showData()
Or like this:
或者像这样：
DHT({'six':6,'seven':'7'}).showData()
or like this:
或者像这样：
# Build the class first
dht = DHT({'six':6,'seven':'7'})
# The call whatever method you want (In our case only 1 method available)
dht.showData()
回答by viraptor
Your constructor is expecting one parameter (data). You're not passing it in the call. I guess you wanted to initialise a field in the object. That would look like this:
您的构造函数需要一个参数（数据）。你没有在通话中传递它。我猜你想初始化对象中的一个字段。那看起来像这样：
class DHT:
def __init__(self):
self.data = {}
self.data['one'] = '1'
self.data['two'] = '2'
self.data['three'] = '3'
def showData(self):
print(self.data)
if __name__ == '__main__':
DHT().showData()
Or even just:
或者甚至只是：
class DHT:
def __init__(self):
self.data = {'one': '1', 'two': '2', 'three': '3'}
def showData(self):
print(self.data)
回答by aIKid
You need to pass some data into it. An empty dictionary, for example.
您需要向其中传递一些数据。例如，空字典。
if __name__ == '__main__': DHT('a').showData()
However, in your example a parameter is not even needed. You can declare it by just:
但是，在您的示例中，甚至不需要参数。您可以通过以下方式声明它：
def __init__(self):
Maybe you mean to set it from the data?
也许您的意思是从数据中设置它？
class DHT:
def __init__(self, data):
self.data['one'] = data['one']
self.data['two'] = data['two']
self.data['three'] = data['three']
def showData(self):
print(self.data)
if __name__ == '__main__': DHT({'one':2, 'two':4, 'three':5}).showData()
showDatawill print the data you just entered.
showData将打印您刚刚输入的数据。
回答by Alexander Zhukov
You should possibly make dataa keyword parameter with a default value of empty dictionary:
您可能应该data使用默认值为空字典的关键字参数：
class DHT:
def __init__(self, data=dict()):
self.data['one'] = '1'
self.data['two'] = '2'
self.data['three'] = '3'
def showData(self):
print(self.data)
if __name__ == '__main__':
DHT().showData()
回答by Eyasu
The problem is with, you
问题是，你
def __init__(self, data):
when you create object from DHT class you should pass parameter the data should be dict type, like
当你从 DHT 类创建对象时，你应该传递参数，数据应该是 dict 类型，比如
data={'one':1,'two':2,'three':3}
dhtObj=DHT(data)
But in your code youshould to change is
但是在你的代码中你应该改变的是
data={'one':1,'two':2,'three':3}
if __name__ == '__main__': DHT(data).showData()
Or
或者
if __name__ == '__main__': DHT({'one':1,'two':2,'three':3}).showData()
