总而言之,我试图将一个字典列表传递给一个容器类,意图是每个字典将用于实例化另一个类.问题是每个字典包含一个要分配给子类的函数对象引用,并且由于某种原因,在最内层子类被实例化之前,它从python函数对象变为c_void_p对象.
应用程序域是使用curses创建基于文本的UI小部件库.
这是容器要包含的’child’类:
class DigitalReadout(Window):
# Just a one-line borderless window displaying some data...
def __init__(self, width, y, x, label, digits, data_source, parent=None):
super(DigitalReadout, self).__init__(1, width, y, x, parent)
self.data_source = data_source
self.data = self.get_data_from_source()
self.label = label
self.digits = digits
self.spaces = self.width - len(self.label) - self.digits # Calc Number of extra spaces
###Irrelevant display-related classes omitted###
def update_data(self):
self.data = self.get_data_from_source() #return data from function
def get_data_from_source(self):
return self.data_source.__call__()
这是’容器’类:
class ReadoutPanel(BoxedWindow):
def __init__(self, y, x, readouts, parent=None):
super(ReadoutPanel,self).__init__(2 + len(readouts), self.find_longest_readout_width(readouts) + 2, y, x, parent)
self.children = []
self.initialize_readouts(readouts)
def find_longest_readout_width(self, readouts):
#Find the longest member and size container accordingly
longest_length = 0
for each_dict in readouts:
this_dict_length = each_dict['digits'] + len(each_dict['label']) + 1
if this_dict_length > longest_length:
longest_length = this_dict_length
return longest_length
def initialize_readouts(self, readouts):
y_readout_index = 1
for each_hash in readouts:
function = each_dict['func']
function()
self.children.append(DigitalReadout(each_dict['digits'] + len(each_dict['label']) + 1,
1,
y_readout_index,
1,
function,
self.window))
作为参考,可以查看基类Window和BoxedWindow here
当我运行以下测试代码时,我得到后续错误:
if __name__ == '__main__':
#standard cuses initialization here...
from time import clock
i = 0
def print_i():
return str(i)
readouts = [{'label': 'count',
'digits': 10,
'func': print_i},
{'label': 'clock',
'digits':10,
'func': print_i}]
readout_panel = ReadoutPanel(1, 1, readouts) #Initialize that puppy!
curses.endwin()
错误:
Traceback (most recent call last):
File "window.py", line 515, in <module>
readout_panel = ReadoutPanel(1, 1, readouts)
File "window.py", line 455, in __init__
self.initialize_readouts(readouts)
File "window.py", line 476, in initialize_readouts
self.window))
File "window.py", line 183, in __init__
self.data = self.data_source()
TypeError: 'c_void_p' object is not callable
Printlining显示该函数正从字典中获取并仍然是一个函数对象.然而,一旦它被传递到DigitalReadout的构造函数中,它就会以某种方式返回一个c_void_p对象.任何想法为什么会这样?
在此先感谢,并为这个可怕的长期问题道歉.
解决方法:
这是DigitalReadout的构造函数:
def __init__(self, width, y, x, label, digits, data_source, parent=None)
这就是你怎么称呼它:
DigitalReadout(each_dict['digits'] + len(each_dict['label']) + 1, # width
1, # y
y_readout_index, # x
1, # label
function, # digits
self.window) # data_source
看起来你在构造函数中缺少一个参数(高?),因为如果我正确读取它,该函数应该是data_source,它现在是数字.