我是Python新手,正在研究存储有关书籍的有意义数据段的类。我已经开始如下:从类__init__方法调用函数时未定义Python全局名称
class BookDisplay:
def __init__(self, _name, _isbn, _price, _picture, _link):
self.name = _name
self.isbn = _isbn
self.price = _price
self.picture = _picture
self.link = _link
self.xmlString = MakeXMLString(_name, _isbn, _price, _picture, _link)
name = ""
isbn = ""
price = 0.0
picture = "" #a URL
link = ""
xmlString = ""
我认为这__init__
方法将只能够调用MakeXMLString
,这是我在同一个文件(bookdisplay.py)定义,正下方BookDisplay
类:
def MakeXMLString(_name, _isbn, _price, _picture, _link): #python multi-line syntax
xmlString = "<name>" + _name + "</name>" \
+ "<isbn>" + _isbn + "</isbn>" \
+ "<price>" + str(_price) + "</price>" \
+ "<picture>" + _picture + "</picture>" \
+ "<link>" + _link + "</link>"
return xmlString
本来,我其实是有MakeXMLString
作为类中的一个方法,像这样:0
def MakeXMLString(self):
self.xmlString = "<name>" + self.name + "</name>" \
+ "<isbn>" + self.isbn + "</isbn>" \
+ "<price>" + str(self.price) + "</price>" \
+ "<picture>" + self.picture + "</picture>" \
+ "<link>" + self.link + "</link>"
在这种情况下,包含在此呼吁:
在这两种情况下,试图实例从另一个文件BookDisplay
时:
from bookdisplay import BookDisplay
...
...
thumbnails = []
...
thumbnails.append(BookDisplay(titleField, "-1", float(priceField), imgField, linkField))
...我碰到下面的全局名称错误(这回溯特别是对于不-within-class功能):
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "search.py", line 30, in ebaySearch
handleDocument(doc)
File "search.py", line 59, in handleDocument
handleItems(items, outputFile)
File "search.py", line 102, in handleItems
thumbnails.append(BookDisplay(titleField, "-1", float(priceField), imgField, linkField))
File "bookdisplay.py", line 15, in __init__
self.xmlString = MakeXMLString(_name, _isbn, _price, _picture, _link)
NameError: global name 'MakeXMLString' is not defined
我在这里失踪了什么?从我所知道的,MakeXMLString
是完全无障碍的课堂。
奇怪的是,我没有从我描述的第一种方法(在类方法之外)进行更改,退出解释器并尝试再次运行所有内容。它以某种方式工作。我不知道为什么。 – nicole 2013-04-30 23:02:51