python - 类型错误 : unbound method setSize() must be called with Page instance as first argument (got classobj instance instead)

Question

当我运行下面提供的代码时，出现以下错误:

类型错误:必须使用 Page 实例作为第一个参数调用未绑定(bind)方法 setSize()(改为使用 int 实例)

In my main, I call a class called Page. The variable pageSize is an integer.

from Page import Page as Page
def main():
   #other code....

   Page.setSize(pageSize)

This is my class of Page:

class Page:
    def __init__(self, frame):
    self.frameId = frame
    self.pageId = -1
    self.timeEvicted = 0
    self.timeLoaded = 0
    self.ifLoaded = False
    self.ownerProcess = 0
    self.referencedWords = []

def initalize(owner, pgId, refdWord, ifLoad):
    self.ownerProcess = owner
    self.pageId = pgId
    addRefdWord(refdWord)
    self.ifLoaded = ifLoad

def setSize(s):
    self.size = s

Answer 1

每个实例方法(可以访问 self 的方法)都必须将 self 作为第一个参数:

def initalize(self, owner, pgId, refdWord, ifLoad):
              ^^^^^

...

def setSize(self, s):
            ^^^^^
    self.size = s

否则，self 不会在函数体中定义。同样，Page.setSize(pageSize) 将不起作用，因为您没有类的实例。您需要在调用实例方法之前创建一个:

page = Page()
page.setSize(pageSize)

现在，page.size == pageSize。