| """Helper class to quickly write a loop over all standard input files. | |
| Typical use is: | |
| import fileinput | |
| for line in fileinput.input(): | |
| process(line) | |
| This iterates over the lines of all files listed in sys.argv[1:], | |
| defaulting to sys.stdin if the list is empty. If a filename is '-' it | |
| is also replaced by sys.stdin. To specify an alternative list of | |
| filenames, pass it as the argument to input(). A single file name is | |
| also allowed. | |
| Functions filename(), lineno() return the filename and cumulative line | |
| number of the line that has just been read; filelineno() returns its | |
| line number in the current file; isfirstline() returns true iff the | |
| line just read is the first line of its file; isstdin() returns true | |
| iff the line was read from sys.stdin. Function nextfile() closes the | |
| current file so that the next iteration will read the first line from | |
| the next file (if any); lines not read from the file will not count | |
| towards the cumulative line count; the filename is not changed until | |
| after the first line of the next file has been read. Function close() | |
| closes the sequence. | |
| Before any lines have been read, filename() returns None and both line | |
| numbers are zero; nextfile() has no effect. After all lines have been | |
| read, filename() and the line number functions return the values | |
| pertaining to the last line read; nextfile() has no effect. | |
| All files are opened in text mode by default, you can override this by | |
| setting the mode parameter to input() or FileInput.__init__(). | |
| If an I/O error occurs during opening or reading a file, the IOError | |
| exception is raised. | |
| If sys.stdin is used more than once, the second and further use will | |
| return no lines, except perhaps for interactive use, or if it has been | |
| explicitly reset (e.g. using sys.stdin.seek(0)). | |
| Empty files are opened and immediately closed; the only time their | |
| presence in the list of filenames is noticeable at all is when the | |
| last file opened is empty. | |
| It is possible that the last line of a file doesn't end in a newline | |
| character; otherwise lines are returned including the trailing | |
| newline. | |
| Class FileInput is the implementation; its methods filename(), | |
| lineno(), fileline(), isfirstline(), isstdin(), nextfile() and close() | |
| correspond to the functions in the module. In addition it has a | |
| readline() method which returns the next input line, and a | |
| __getitem__() method which implements the sequence behavior. The | |
| sequence must be accessed in strictly sequential order; sequence | |
| access and readline() cannot be mixed. | |
| Optional in-place filtering: if the keyword argument inplace=1 is | |
| passed to input() or to the FileInput constructor, the file is moved | |
| to a backup file and standard output is directed to the input file. | |
| This makes it possible to write a filter that rewrites its input file | |
| in place. If the keyword argument backup=".<some extension>" is also | |
| given, it specifies the extension for the backup file, and the backup | |
| file remains around; by default, the extension is ".bak" and it is | |
| deleted when the output file is closed. In-place filtering is | |
| disabled when standard input is read. XXX The current implementation | |
| does not work for MS-DOS 8+3 filesystems. | |
| Performance: this module is unfortunately one of the slower ways of | |
| processing large numbers of input lines. Nevertheless, a significant | |
| speed-up has been obtained by using readlines(bufsize) instead of | |
| readline(). A new keyword argument, bufsize=N, is present on the | |
| input() function and the FileInput() class to override the default | |
| buffer size. | |
| XXX Possible additions: | |
| - optional getopt argument processing | |
| - isatty() | |
| - read(), read(size), even readlines() | |
| """ | |
| import sys, os | |
| __all__ = ["input","close","nextfile","filename","lineno","filelineno", | |
| "isfirstline","isstdin","FileInput"] | |
| _state = None | |
| DEFAULT_BUFSIZE = 8*1024 | |
| def input(files=None, inplace=0, backup="", bufsize=0, | |
| mode="r", openhook=None): | |
| """input([files[, inplace[, backup[, mode[, openhook]]]]]) | |
| Create an instance of the FileInput class. The instance will be used | |
| as global state for the functions of this module, and is also returned | |
| to use during iteration. The parameters to this function will be passed | |
| along to the constructor of the FileInput class. | |
| """ | |
| global _state | |
| if _state and _state._file: | |
| raise RuntimeError, "input() already active" | |
| _state = FileInput(files, inplace, backup, bufsize, mode, openhook) | |
| return _state | |
| def close(): | |
| """Close the sequence.""" | |
| global _state | |
| state = _state | |
| _state = None | |
| if state: | |
| state.close() | |
| def nextfile(): | |
| """ | |
| Close the current file so that the next iteration will read the first | |
| line from the next file (if any); lines not read from the file will | |
| not count towards the cumulative line count. The filename is not | |
| changed until after the first line of the next file has been read. | |
| Before the first line has been read, this function has no effect; | |
| it cannot be used to skip the first file. After the last line of the | |
| last file has been read, this function has no effect. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.nextfile() | |
| def filename(): | |
| """ | |
| Return the name of the file currently being read. | |
| Before the first line has been read, returns None. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.filename() | |
| def lineno(): | |
| """ | |
| Return the cumulative line number of the line that has just been read. | |
| Before the first line has been read, returns 0. After the last line | |
| of the last file has been read, returns the line number of that line. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.lineno() | |
| def filelineno(): | |
| """ | |
| Return the line number in the current file. Before the first line | |
| has been read, returns 0. After the last line of the last file has | |
| been read, returns the line number of that line within the file. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.filelineno() | |
| def fileno(): | |
| """ | |
| Return the file number of the current file. When no file is currently | |
| opened, returns -1. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.fileno() | |
| def isfirstline(): | |
| """ | |
| Returns true the line just read is the first line of its file, | |
| otherwise returns false. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.isfirstline() | |
| def isstdin(): | |
| """ | |
| Returns true if the last line was read from sys.stdin, | |
| otherwise returns false. | |
| """ | |
| if not _state: | |
| raise RuntimeError, "no active input()" | |
| return _state.isstdin() | |
| class FileInput: | |
| """class FileInput([files[, inplace[, backup[, mode[, openhook]]]]]) | |
| Class FileInput is the implementation of the module; its methods | |
| filename(), lineno(), fileline(), isfirstline(), isstdin(), fileno(), | |
| nextfile() and close() correspond to the functions of the same name | |
| in the module. | |
| In addition it has a readline() method which returns the next | |
| input line, and a __getitem__() method which implements the | |
| sequence behavior. The sequence must be accessed in strictly | |
| sequential order; random access and readline() cannot be mixed. | |
| """ | |
| def __init__(self, files=None, inplace=0, backup="", bufsize=0, | |
| mode="r", openhook=None): | |
| if isinstance(files, basestring): | |
| files = (files,) | |
| else: | |
| if files is None: | |
| files = sys.argv[1:] | |
| if not files: | |
| files = ('-',) | |
| else: | |
| files = tuple(files) | |
| self._files = files | |
| self._inplace = inplace | |
| self._backup = backup | |
| self._bufsize = bufsize or DEFAULT_BUFSIZE | |
| self._savestdout = None | |
| self._output = None | |
| self._filename = None | |
| self._lineno = 0 | |
| self._filelineno = 0 | |
| self._file = None | |
| self._isstdin = False | |
| self._backupfilename = None | |
| self._buffer = [] | |
| self._bufindex = 0 | |
| # restrict mode argument to reading modes | |
| if mode not in ('r', 'rU', 'U', 'rb'): | |
| raise ValueError("FileInput opening mode must be one of " | |
| "'r', 'rU', 'U' and 'rb'") | |
| self._mode = mode | |
| if inplace and openhook: | |
| raise ValueError("FileInput cannot use an opening hook in inplace mode") | |
| elif openhook and not hasattr(openhook, '__call__'): | |
| raise ValueError("FileInput openhook must be callable") | |
| self._openhook = openhook | |
| def __del__(self): | |
| self.close() | |
| def close(self): | |
| self.nextfile() | |
| self._files = () | |
| def __iter__(self): | |
| return self | |
| def next(self): | |
| try: | |
| line = self._buffer[self._bufindex] | |
| except IndexError: | |
| pass | |
| else: | |
| self._bufindex += 1 | |
| self._lineno += 1 | |
| self._filelineno += 1 | |
| return line | |
| line = self.readline() | |
| if not line: | |
| raise StopIteration | |
| return line | |
| def __getitem__(self, i): | |
| if i != self._lineno: | |
| raise RuntimeError, "accessing lines out of order" | |
| try: | |
| return self.next() | |
| except StopIteration: | |
| raise IndexError, "end of input reached" | |
| def nextfile(self): | |
| savestdout = self._savestdout | |
| self._savestdout = 0 | |
| if savestdout: | |
| sys.stdout = savestdout | |
| output = self._output | |
| self._output = 0 | |
| if output: | |
| output.close() | |
| file = self._file | |
| self._file = 0 | |
| if file and not self._isstdin: | |
| file.close() | |
| backupfilename = self._backupfilename | |
| self._backupfilename = 0 | |
| if backupfilename and not self._backup: | |
| try: os.unlink(backupfilename) | |
| except OSError: pass | |
| self._isstdin = False | |
| self._buffer = [] | |
| self._bufindex = 0 | |
| def readline(self): | |
| try: | |
| line = self._buffer[self._bufindex] | |
| except IndexError: | |
| pass | |
| else: | |
| self._bufindex += 1 | |
| self._lineno += 1 | |
| self._filelineno += 1 | |
| return line | |
| if not self._file: | |
| if not self._files: | |
| return "" | |
| self._filename = self._files[0] | |
| self._files = self._files[1:] | |
| self._filelineno = 0 | |
| self._file = None | |
| self._isstdin = False | |
| self._backupfilename = 0 | |
| if self._filename == '-': | |
| self._filename = '<stdin>' | |
| self._file = sys.stdin | |
| self._isstdin = True | |
| else: | |
| if self._inplace: | |
| self._backupfilename = ( | |
| self._filename + (self._backup or os.extsep+"bak")) | |
| try: os.unlink(self._backupfilename) | |
| except os.error: pass | |
| # The next few lines may raise IOError | |
| os.rename(self._filename, self._backupfilename) | |
| self._file = open(self._backupfilename, self._mode) | |
| try: | |
| perm = os.fstat(self._file.fileno()).st_mode | |
| except OSError: | |
| self._output = open(self._filename, "w") | |
| else: | |
| fd = os.open(self._filename, | |
| os.O_CREAT | os.O_WRONLY | os.O_TRUNC, | |
| perm) | |
| self._output = os.fdopen(fd, "w") | |
| try: | |
| if hasattr(os, 'chmod'): | |
| os.chmod(self._filename, perm) | |
| except OSError: | |
| pass | |
| self._savestdout = sys.stdout | |
| sys.stdout = self._output | |
| else: | |
| # This may raise IOError | |
| if self._openhook: | |
| self._file = self._openhook(self._filename, self._mode) | |
| else: | |
| self._file = open(self._filename, self._mode) | |
| self._buffer = self._file.readlines(self._bufsize) | |
| self._bufindex = 0 | |
| if not self._buffer: | |
| self.nextfile() | |
| # Recursive call | |
| return self.readline() | |
| def filename(self): | |
| return self._filename | |
| def lineno(self): | |
| return self._lineno | |
| def filelineno(self): | |
| return self._filelineno | |
| def fileno(self): | |
| if self._file: | |
| try: | |
| return self._file.fileno() | |
| except ValueError: | |
| return -1 | |
| else: | |
| return -1 | |
| def isfirstline(self): | |
| return self._filelineno == 1 | |
| def isstdin(self): | |
| return self._isstdin | |
| def hook_compressed(filename, mode): | |
| ext = os.path.splitext(filename)[1] | |
| if ext == '.gz': | |
| import gzip | |
| return gzip.open(filename, mode) | |
| elif ext == '.bz2': | |
| import bz2 | |
| return bz2.BZ2File(filename, mode) | |
| else: | |
| return open(filename, mode) | |
| def hook_encoded(encoding): | |
| import codecs | |
| def openhook(filename, mode): | |
| return codecs.open(filename, mode, encoding) | |
| return openhook | |
| def _test(): | |
| import getopt | |
| inplace = 0 | |
| backup = 0 | |
| opts, args = getopt.getopt(sys.argv[1:], "ib:") | |
| for o, a in opts: | |
| if o == '-i': inplace = 1 | |
| if o == '-b': backup = a | |
| for line in input(args, inplace=inplace, backup=backup): | |
| if line[-1:] == '\n': line = line[:-1] | |
| if line[-1:] == '\r': line = line[:-1] | |
| print "%d: %s[%d]%s %s" % (lineno(), filename(), filelineno(), | |
| isfirstline() and "*" or "", line) | |
| print "%d: %s[%d]" % (lineno(), filename(), filelineno()) | |
| if __name__ == '__main__': | |
| _test() |