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我需要将 Matlab fread 翻译成 python，特别是允许读取二维数组并在读取时跳过数据。我想出了以下方法，但我想可能有更有效和“pythonic”的方法来做到这一点（我绝不是程序员）。有什么建议吗？请注意，我无法读取整个文件，然后对数组进行二次采样，因为要读取的文件太大。

def FromFileSkip(fid, count=1, skip=0, dtype=np.float32):
    if np.ndim(count)==0:
        if skip>=0:
            data = np.zeros(count, dtype=dtype)
            k = 0
            while k<count:
                data[k] = np.fromfile(fid, count=1, dtype=dtype)
                fid.seek(skip, 1)
                k +=1
            return data
    elif np.ndim(count)==1:
        if skip>0:
            data = np.zeros(count, dtype=dtype)
            k = 0
            while k<count[1]:
                data[:,k] = np.fromfile(fid, count=count[0], dtype=dtype)
                fid.seek(skip, 1)
                k +=1
            return data
    else:
        raise ValueError('File can be read only into 1d or 2d arrays')
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1 回答 1

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这或多或少是你所拥有的，也许只是更清洁一点。

def fromfileskip(fid,shape,counts,skip,dtype):
  """
  fid    : file object,    Should be open binary file.
  shape  : tuple of ints,  This is the desired shape of each data block.
           For a 2d array with xdim,ydim = 3000,2000 and xdim = fastest 
           dimension, then shape = (2000,3000).
  counts : int, Number of times to read a data block.
  skip   : int, Number of bytes to skip between reads.
  dtype  : np.dtype object, Type of each binary element.
  """
  data = np.zeros((counts,)  + shape)
  for c in xrange(counts):
    block = np.fromfile(fid,dtype=np.float32,count=np.product(shape))
    data[c] = block.reshape(shape)
    fid.seek( fid.tell() + skip)

  return data
于 2013-04-02T01:40:02.707 回答