具有所需的\u arg、*args、**kwargs的类定义

Question

我想使用一个必需的_arg除了*args，**kwarg在一个来自另一个类的类中。但目前我没有成功！！！ 这段代码：

class PageNumCanvas(canvas.Canvas):
    "For  add \"page number of total\" in each footer."

    def __init__(self, page1, *args, **kwargs):
        "Constructor."
        self.page1 = page1 - 1
        canvas.Canvas.__init__(self, *args, **kwargs)
        self.pages = []

执行此操作时的错误消息：canvasmaker = PageNumCanvas(1)：

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如何使用page1参数调用PageNumCanvas类？在

更新1：

如果我不在类的init中使用参数，我就没有问题了。例如：

>>> from reportlab.pdfgen import canvas
>>> class PageNumCanvas(canvas.Canvas):
...     "For  add \"page number of total\" in each footer."
...     def __init__(self, *args, **kwargs):
...             canvas.Canvas.__init__(self, *args, **kwargs)
...             self.pages = []
... 
>>> canvasmaker = PageNumCanvas(1)
>>> canvasmaker
<__main__.PageNumCanvas instance at 0x7f618195df38>
>>> 

更新2： 多亏了goncalopp让路，正确的代码是：

class PageNumCanvas(canvas.Canvas):
...     "For  add \"page number of total\" in each footer."
...     def __init__(self, page1, *args, **kwargs):
...             "Constructor."
...             canvas.Canvas.__init__(self, page1, *args, **kwargs)
...             self.page1 = page1 - 1
...             self.pages = []
...             print self.page1
... 
>>> canvasmaker = PageNumCanvas(12)
11
>>> 

Answer 1

你可能在找

canvas.Canvas.__init__(self, page1, *args, **kwargs)

Answer 2

{1}你需要提供一个{1}的例子。在

您的第二个版本没有给您错误的原因是您仍然在传递1，因为您删除了page1参数，所以它被传递给了Canvas构造函数。在

要使其正常工作，只需输入名称和页码：

from reportlab.pdfgen import canvas
class PageNumCanvas(canvas.Canvas):
    "For  add \"page number of total\" in each footer."

    def __init__(self, page1, *args, **kwargs):
        "Constructor."
        self.page1 = page1 - 1
        canvas.Canvas.__init__(self, *args, **kwargs)
        self.pages = []

canvasmaker = PageNumCanvas(1, "Hello.pdf")
print canvasmaker.page1

输出

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