关闭文件错误的I / O操作以及如何解决它

Question

下面的简单代码包含一些I / O操作。我在关闭文件错误时遇到 I / O操作，并想知道我做错了什么以及如何修复它。

def externalSortStream(iterator, partId=0, reverse=False, keyfunc=None, serial=serializer, limit=10, batch=100):
"""
Given an iterator, returns an iterator of sorted elements (according to parameters). 

:param iterator: iterator. Expects (Key, Value).
:param keyfunc: function applied on the keykey.
:param reverse: Reverse default ordering if true. (default is ascending; reverse is descending) 
:param serializer: See README.
:param limit: memory limit.
:param batch: Number of elements to read at a time.
"""

all_runs = [] # can be used to hold a list of iterators
run = [] # used to hold the current run of elements

def load(fileobj):
    """
    Returns a generator object that outputs elements 
    from a serialized (saved) stream. Closes the file when done.

    :param fileobj: python object file
    """
    for _ in serial.load_stream(fileobj):
        yield _
    fileobj.close()

# TODO everywhere below 
n = 0
fileList = []
while True:
    c = list(itertools.islice(iterator, batch))
    run += c
    # TODO

    if len(c) != batch:
        #last group
        run = sorted(run, key = lambda ele: ele[0])
        filename = get_sort_dir(partId, n)
        fileList.append(filename)
        with open(filename, "w+") as writeFile:
            serializer.dump_stream(run, writeFile)


        break

    if get_used_memory() > limit: # TODO

        run = sorted(run, key = lambda ele: ele[0])
        filename = get_sort_dir(partId, n)
        fileList.append(filename)
        with open(filename, "w+") as writeFile:
            serializer.dump_stream(run, writeFile)

        n += 1
        run = []

# TODO some cleanup stuff
for fi in fileList:
    #for each file, open, close, then delete
    with open(fi, "r") as current:

        all_runs.append(load(current))
    os.unlink(fi)

return heapq.merge(all_runs, key=lambda x: keyfunc(x[0]), reverse=reverse)

完整追溯：

ValueError

Traceback (most recent call last)
<ipython-input-18-4e28c39b6fbb> in <module>()
      1 test_stream = ((i, i) for i in range(100))
----> 2 list(externalSortStream(test_stream, keyfunc=(lambda x: abs(50 - (x ** 2)))))[:10]

heapq3.py in merge(iterables, key, reverse)
    651     for order, it in enumerate(map(iter, iterables)):
    652         try:
--> 653             value = next(it)
    654             h_append([key(value), order * direction, value, it])
    655         except StopIteration:

<ipython-input-15-ec61ab2b349c> in load(fileobj)
     21         :param fileobj: python object file
     22         """
---> 23         for _ in serial.load_stream(fileobj):
     24             yield _
     25         fileobj.close()

serializers.py in load_stream(self, stream)
    137         while True:
    138             try:
--> 139                 yield self._read_with_length(stream)
    140             except EOFError:
    141                 return

serializers.py in _read_with_length(self, stream)
    154 
    155     def _read_with_length(self, stream):
--> 156         length = read_int(stream)
    157         if length == SpecialLengths.END_OF_DATA_SECTION:
    158             raise EOFError

serializers.py in read_int(stream)
    541 
    542 def read_int(stream):
--> 543     length = stream.read(4)
    544     if not length:
    545         raise EOFError

ValueError: I/O operation on closed file

Answer 1

第4行至最后一行：

 with open(fi, "r") as current:

需要更改为：

current = open(fi, "r")

就是这样。这解决了我的问题。 load（）关闭当前，显然我无法关闭中的当前与当前的open（）as ... 代码段