177 lines
6.4 KiB
Python
177 lines
6.4 KiB
Python
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# Copyright (c) 2000 David Abrahams. Permission to copy, use, modify, sell
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# and distribute this software is granted provided this copyright
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# notice appears in all copies. This software is provided "as is" without
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# express or implied warranty, and with no claim as to its suitability for
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# any purpose.
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"""Provides a class Stdin which can be used to emulate the regular old
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sys.stdin for the PythonWin interactive window. Right now it just pops
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up a raw_input() dialog. With luck, someone will integrate it into the
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actual PythonWin interactive window someday.
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WARNING: Importing this file automatically replaces sys.stdin with an
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instance of Stdin (below). This is useful because you can just open
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Stdin.py in PythonWin and hit the import button to get it set up right
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if you don't feel like changing PythonWin's source. To put things back
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the way they were, simply use this magic incantation:
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import sys
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sys.stdin = sys.stdin.real_file
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"""
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import sys
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try:
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get_input_line = raw_input # py2x
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except NameError:
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get_input_line = input # py3k
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class Stdin:
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def __init__(self):
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self.real_file = sys.stdin # NOTE: Likely to be None in py3k
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self.buffer = ""
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self.closed = False
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def __getattr__(self, name):
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"""Forward most functions to the real sys.stdin for absolute realism."""
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if self.real_file is None:
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raise AttributeError(name)
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return getattr(self.real_file, name)
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def isatty(self):
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"""Return 1 if the file is connected to a tty(-like) device, else 0."""
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return 1
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def read(self, size=-1):
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"""Read at most size bytes from the file (less if the read
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hits EOF or no more data is immediately available on a pipe,
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tty or similar device). If the size argument is negative or
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omitted, read all data until EOF is reached. The bytes are
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returned as a string object. An empty string is returned when
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EOF is encountered immediately. (For certain files, like ttys,
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it makes sense to continue reading after an EOF is hit.)"""
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result_size = self.__get_lines(size)
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return self.__extract_from_buffer(result_size)
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def readline(self, size=-1):
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"""Read one entire line from the file. A trailing newline
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character is kept in the string2.6 (but may be absent when a file ends
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with an incomplete line). If the size argument is present and
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non-negative, it is a maximum byte count (including the trailing
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newline) and an incomplete line may be returned. An empty string is
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returned when EOF is hit immediately. Note: unlike stdio's fgets(),
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the returned string contains null characters ('\0') if they occurred
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in the input.
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"""
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maximum_result_size = self.__get_lines(size, lambda buffer: "\n" in buffer)
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if "\n" in self.buffer[:maximum_result_size]:
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result_size = self.buffer.find("\n", 0, maximum_result_size) + 1
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assert result_size > 0
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else:
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result_size = maximum_result_size
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return self.__extract_from_buffer(result_size)
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def __extract_from_buffer(self, character_count):
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"""Remove the first character_count characters from the internal buffer and
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return them.
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"""
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result = self.buffer[:character_count]
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self.buffer = self.buffer[character_count:]
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return result
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def __get_lines(self, desired_size, done_reading=lambda buffer: False):
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"""Keep adding lines to our internal buffer until done_reading(self.buffer)
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is true or EOF has been reached or we have desired_size bytes in the buffer.
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If desired_size < 0, we are never satisfied until we reach EOF. If done_reading
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is not supplied, it is not consulted.
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If desired_size < 0, returns the length of the internal buffer. Otherwise,
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returns desired_size.
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"""
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while not done_reading(self.buffer) and (
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desired_size < 0 or len(self.buffer) < desired_size
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):
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try:
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self.__get_line()
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except (
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EOFError,
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KeyboardInterrupt,
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): # deal with cancellation of get_input_line dialog
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desired_size = len(self.buffer) # Be satisfied!
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if desired_size < 0:
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return len(self.buffer)
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else:
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return desired_size
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def __get_line(self):
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"""Grab one line from get_input_line() and append it to the buffer."""
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line = get_input_line()
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print(">>>", line) # echo input to console
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self.buffer = self.buffer + line + "\n"
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def readlines(self, *sizehint):
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"""Read until EOF using readline() and return a list containing the lines
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thus read. If the optional sizehint argument is present, instead of
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reading up to EOF, whole lines totalling approximately sizehint bytes
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(possibly after rounding up to an internal buffer size) are read.
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"""
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result = []
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total_read = 0
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while sizehint == () or total_read < sizehint[0]:
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line = self.readline()
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if line == "":
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break
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total_read = total_read + len(line)
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result.append(line)
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return result
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if __name__ == "__main__":
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test_input = r"""this is some test
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input that I am hoping
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~
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will be very instructive
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and when I am done
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I will have tested everything.
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Twelve and twenty blackbirds
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baked in a pie. Patty cake
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patty cake so am I.
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~
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Thirty-five niggling idiots!
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Sell you soul to the devil, baby
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"""
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def fake_raw_input(prompt=None):
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"""Replacement for raw_input() which pulls lines out of global test_input.
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For testing only!
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"""
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global test_input
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if "\n" not in test_input:
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end_of_line_pos = len(test_input)
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else:
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end_of_line_pos = test_input.find("\n")
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result = test_input[:end_of_line_pos]
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test_input = test_input[end_of_line_pos + 1 :]
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if len(result) == 0 or result[0] == "~":
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raise EOFError()
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return result
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get_input_line = fake_raw_input
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# Some completely inadequate tests, just to make sure the code's not totally broken
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try:
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x = Stdin()
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print(x.read())
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print(x.readline())
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print(x.read(12))
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print(x.readline(47))
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print(x.readline(3))
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print(x.readlines())
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finally:
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get_input_line = raw_input
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else:
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import sys
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sys.stdin = Stdin()
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