一个类的例子

Question

任何人都可以帮助我理解为什么这会给我一个错误？错误是“NameError：name'self'未定义”。我的代码中有一个类似的类，并且工作正常吗？

我正在使用'xlrd'，team是对workbook.sheet_by_name的引用。

class Rollout:                                  
    def __init__(self, team, name):
        self.team = team
        self.name = name
        self.jobs = {}
        self.start_row = 1
        self.last_row = self.team.nrows

    for i in range(self.start_row,self.last_row):
            try:
                self.jobs[i-1] =   [str(self.team.cell_value(i,0)).upper(), \
                                    str(self.team.cell_value(i,1)).upper(), \
                                    str(self.team.cell_value(i,2)).upper(), \
                                    str(self.team.cell_value(i,3)).upper(), \
                                    str(xlrd.xldate_as_tuple(self.team.cell_value(i,4),0)[3]), \
                                    str(self.team.cell_value(i,5)).upper(), \
                                    str(self.team.cell_value(i,6)).upper()]
            except ValueError:
                print "It look's like one of your 'time' cells is incorrect!"
                self.jobs[i-1] =   [str(self.team.cell_value(i,0)).upper(), \
                                    str(self.team.cell_value(i,1)).upper(), \
                                    str(self.team.cell_value(i,2)).upper(), \
                                    str(self.team.cell_value(i,3)).upper(), \
                                    "missing", \
                                    str(self.team.cell_value(i,5)).upper(), \
                                    str(self.team.cell_value(i,6)).upper()]

Answer 1

for循环错误地缩进，导致它超出了该方法的范围，但在类的范围内。这反过来意味着self未定义。

Python确实解释了该类范围内的循环代码，但没有该对象的实例。示例格式错误的代码：

class Simple(object):
    def __init__(self, a):
        self.a = a

    print("Here we go!")
    for i in xrange(self.a):
        print(i)

回溯

$ python simple.py
Here we go!
Traceback (most recent call last):
  File "simple.py", line 4, in <module>
    class Simple(object):
  File "simple.py", line 9, in Simple
    for i in xrange(self.a):
NameError: name 'self' is not defined

Answer 2

我在执行代码时遇到了同样的错误，

#An example of a class
class Shape:
    def __init__(self,x,y):
        self.x = x
        self.y = y
    description = "This shape has not been described yet"
    author = "Nobody has claimed to make this shape yet"
    def area(self):
        return self.x * self.y
    def perimeter(self):
        return 2 * self.x + 2 * self.y
    def describe(self,text):
        self.description = text
    def authorName(self,text):
        self.author = text
    def scaleSize(self,scale):
        self.x = self.x * scale
    self.y = self.y * scale

然后我在代码的最后一行之前保留空间，如

#An example of a class
class Shape:
    def __init__(self,x,y):
        self.x = x
        self.y = y
    description = "This shape has not been described yet"
    author = "Nobody has claimed to make this shape yet"
    def area(self):
        return self.x * self.y
    def perimeter(self):
        return 2 * self.x + 2 * self.y
    def describe(self,text):
        self.description = text
    def authorName(self,text):
        self.author = text
    def scaleSize(self,scale):
        self.x = self.x * scale
        self.y = self.y * scale

然后没有错误，所以空间就是问题..

Answer 3

*

另一方面

*，如果您在构造函数（ init ）参数中忽略“self”关键字，那么您将获得：

    NameError: name 'self' is not defined

每当你在构造函数方法体中使用“self”时。

Answer 4

一个类的例子

class Shape:
    def __init__(self,x,y):
        self.x = x
        self.y = y
    description = "This shape has not been described yet"
    author = "Nobody has claimed to make this shape yet"
    def area(self):
        return self.x * self.y
    def perimeter(self):
        return 2 * self.x + 2 * self.y
    def describe(self,text):
        self.description = text
    def authorName(self,text):
        self.author = text
    def scaleSize(self,scale):
        self.x = self.x * scale
        self.y = self.y * scale

NameError：名称'self'未定义，即使它是？

4 个答案:

一个类的例子