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1630
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aaronmk
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# I/O
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class StreamIter:
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'''Iterates over the lines in a stream.
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Unlike stream.__iter__(), doesn't wait for EOF to start returning lines.
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Offers curr() method.
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Forwards close() to the underlying stream.
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'''
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def __init__(self, stream):
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self.stream = stream
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self.line = None
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def __iter__(self): return self
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def curr(self):
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if self.line == None: self.line = self.stream.readline()
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if self.line == '': raise StopIteration
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return self.line
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def next(self):
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line = self.curr()
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self.line = None
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return line
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def close(self): self.stream.close()
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class TracedOutputStream:
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'''Wraps an output stream, running a trace function on each string written
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'''
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def __init__(self, trace, stream):
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self.trace = trace
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self.stream = stream
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def write(self, str_):
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self.trace(str_)
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return self.stream.write(str_)
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class LineCountOutputStream(TracedOutputStream):
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'''Wraps an output stream, making the current line number available.
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Lines start counting from 1.'''
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def __init__(self, stream):
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self.line_num = 1
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def trace(str_): self.line_num += str_.count('\n')
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TracedOutputStream.__init__(self, trace, stream)
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