Operator += works once, fails if called again

[Frederic Rentsch]

Hi all,

   I have a class Time_Series derived from list. It lists days and 
contains a dictionary of various Lists also derived from list which 
contain values related to said days. (e.g. Stock quotes, volumes traded, 
etc.)
   I defined an operator += which works just fine, but only once. If I 
repeat the operation, it fails and leaves me utterly mystified and crushed.

Craving to be uncrushed by a superior intelligence.

Frederic


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A test:

 >>> TS1 = TIME_SERIES_7.Time_Series (range (10), 'TS1')  # Some days
 >>> L1 = LIST_7.Floats ((22,44,323,55,344,55,66,77,-1,0), 'Numbers')    
# Some List with values
 >>> TS1.add_List (L1)
 >>> TS2 = TIME_SERIES_7.Time_Series ((3,4,5,7,8), 'TS2')  # Other days 
(subset)
 >>> L2 = LIST_7.Floats ((7,-2,-5,0,2), 'Numbers')   # Another List with 
values
 >>> TS2.add_list (L2)
 >>> TS1 += TS2    # First call
 >> TS1.write ()
TS1  | Date       | Numbers |

0.00 | 1900.00.00 |   22.00 |
1.00 | 1900.01.01 |   44.00 |
2.00 | 1900.01.02 |  323.00 |
3.00 | 1900.01.03 |   62.00 |
4.00 | 1900.01.04 |  342.00 |
5.00 | 1900.01.05 |   50.00 |
6.00 | 1900.01.06 |   63.00 |
7.00 | 1900.01.07 |   77.00 |
8.00 | 1900.01.08 |   -1.00 |
9.00 | 1900.01.09 |    0.00 |

Perfect!

 >>> TS1 += TS2    # Second call

Traceback (most recent call last):
  File "<pyshell#311>", line 1, in -toplevel-
    TS += TS2
  File "c:\i\sony\fre\src\python\TIME_SERIES_7.py", line 1314, in __iadd__
    return self.__add__ (other)
  File "c:\i\sony\fre\src\python\TIME_SERIES_7.py", line 1273, in __add__
    Sum = copy.deepcopy (self)
  File "C:\PYTHON24\lib\copy.py", line 188, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "C:\PYTHON24\lib\copy.py", line 335, in _reconstruct
    state = deepcopy(state, memo)
  File "C:\PYTHON24\lib\copy.py", line 161, in deepcopy
    y = copier(x, memo)
  File "C:\PYTHON24\lib\copy.py", line 252, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "C:\PYTHON24\lib\copy.py", line 161, in deepcopy
    y = copier(x, memo)
  File "C:\PYTHON24\lib\copy.py", line 252, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "C:\PYTHON24\lib\copy.py", line 188, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "C:\PYTHON24\lib\copy.py", line 335, in _reconstruct
    state = deepcopy(state, memo)
  File "C:\PYTHON24\lib\copy.py", line 161, in deepcopy
    y = copier(x, memo)
  File "C:\PYTHON24\lib\copy.py", line 252, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "C:\PYTHON24\lib\copy.py", line 188, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "C:\PYTHON24\lib\copy.py", line 320, in _reconstruct
    y = callable(*args)
  File "C:\PYTHON24\lib\copy_reg.py", line 92, in __newobj__
    return cls.__new__(cls, *args)
TypeError: instancemethod expected at least 2 arguments, got 0


It seems to crash on the second call to deepcopy. Why? The type of the 
deepcopied object is still 'Time_Series'.

Here's Time_Series.__add__ () but I don't think there's anything wrong 
with that.

   def __add__ (self, other):

      if self [0] <= other [0]: # One or the other ...
         Sum = copy.deepcopy (self)
         Summand = copy.deepcopy (other)
      else: # depending on which starts earlier
         Sum = copy.deepcopy (other)
         Summand = copy.deepcopy (self)

      if Sum [0] != Summand [0]:
         Summand.insert (0, Sum [0])
         for list_name in Summand.Lists:
            Summand.Lists [list_name].insert (0, None)
      if Sum [-1] < Summand [-1]:
         Sum.append (Summand [-1])
      elif Sum [-1] > Summand [-1]:
         Summand.append (Sum [-1])

      Sum.make_continuous ()          # Fills in missing days and values
      Summand.make_continuous ()

      for list_name in Summand.Lists:
         if Sum.Lists.has_key (list_name):
            Sum.Lists [list_name] += Summand.Lists [list_name]
            # List operators work fine

      return Sum


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