From d1dc47558cebcf96ff5ead93df8b46b76e76a004 Mon Sep 17 00:00:00 2001 From: Greg Ward Date: Wed, 13 Jan 1999 16:12:04 +0000 Subject: [PATCH] Added: mems.lib.text_file: provides TextFile class for parsing text files with (optional) comment stripping, blank line skipping, whitespace removal, and line joining with trailing backslashes. --- Lib/distutils/text_file.py | 206 +++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 Lib/distutils/text_file.py diff --git a/Lib/distutils/text_file.py b/Lib/distutils/text_file.py new file mode 100644 index 00000000000..9fff941ec90 --- /dev/null +++ b/Lib/distutils/text_file.py @@ -0,0 +1,206 @@ +"""text_file + +provides the TextFile class, which gives an interface to text files +that (optionally) takes care of stripping comments, ignoring blank +lines, and joining lines with backslashes.""" + +# created 1999/01/12, Greg Ward + +__revision__ = "$Id$" + +from types import * +import os, string, re + + +class TextFile: + filename = None + file = None + current_line = None + + default_options = { 'strip_comments': 1, + 'comment_re': re.compile (r'\s*#.*'), + 'skip_blanks': 1, + 'join_lines': 0, + 'lstrip_ws': 0, + 'rstrip_ws': 1, + } + + def __init__ (self, filename=None, **options): + + # set values for all options -- either from client option hash + # or fallback to default_options + for opt in self.default_options.keys(): + if options.has_key (opt): + if opt == 'comment_re' and type (options[opt]) is StringType: + self.comment_re = re.compile (options[opt]) + else: + setattr (self, opt, options[opt]) + + else: + setattr (self, opt, self.default_options[opt]) + + # sanity check client option hash + for opt in options.keys(): + if not self.default_options.has_key (opt): + raise KeyError, "invalid TextFile option '%s'" % opt + + self.filename = filename + if self.filename: + self.open () + + + def open (self, filename=None): + if not self.filename: + if not filename: + raise RuntimeError, "must provide a filename somehow" + + self.filename = filename + + self.file = open (self.filename, 'r') + self.current_line = 0 + + + def close (self): + self.file.close () + self.file = None + self.filename = None + self.current_line = None + + + def readline (self): + + buildup_line = '' + + while 1: + # read the line, optionally strip comments + line = self.file.readline() + if self.strip_comments and line: + line = self.comment_re.sub ('', line) + + # did previous line end with a backslash? then accumulate + if self.join_lines and buildup_line: + # oops: end of file + if not line: + self.warn ("continuation line immediately precedes " + "end-of-file") + return buildup_line + + line = buildup_line + line + + # careful: pay attention to line number when incrementing it + if type (self.current_line) is ListType: + self.current_line[1] = self.current_line[1] + 1 + else: + self.current_line = [self.current_line, self.current_line+1] + # just an ordinary line, read it as usual + else: + if not line: + return None + + # still have to be careful about incrementing the line number! + if type (self.current_line) is ListType: + self.current_line = self.current_line[1] + 1 + else: + self.current_line = self.current_line + 1 + + + # strip whitespace however the client wants (leading and + # trailing, or one or the other, or neither) + if self.lstrip_ws and self.rstrip_ws: + line = string.strip (line) + else: + if self.lstrip_ws: + line = string.lstrip (line) + if self.rstrip_ws: + line = string.rstrip (line) + + # blank line (whether we rstrip'ed or not)? skip to next line + # if appropriate + if line == '' or line == '\n' and self.skip_blanks: + continue + + if self.join_lines: + if line[-1] == '\\': + buildup_line = line[:-1] + continue + + if line[-2:] == '\\\n': + buildup_line = line[0:-2] + '\n' + continue + + # well, I guess there's some actual content there: return it + return line + + # end readline + + + def readlines (self): + lines = [] + while 1: + line = self.readline() + if line is None: + return lines + lines.append (line) + + +if __name__ == "__main__": + test_data = """# test file + +line 3 \\ +continues on next line +""" + + # result 1: no fancy options + result1 = map (lambda x: x + "\n", string.split (test_data, "\n")[0:-1]) + + # result 2: just strip comments + result2 = ["\n", "\n", "line 3 \\\n", "continues on next line\n"] + + # result 3: just strip blank lines + result3 = ["# test file\n", "line 3 \\\n", "continues on next line\n"] + + # result 4: default, strip comments, blank lines, and trailing whitespace + result4 = ["line 3 \\", "continues on next line"] + + # result 5: full processing, strip comments and blanks, plus join lines + result5 = ["line 3 continues on next line"] + + def test_input (count, description, file, expected_result): + result = file.readlines () + # result = string.join (result, '') + if result == expected_result: + print "ok %d (%s)" % (count, description) + else: + print "not ok %d (%s):" % (count, description) + print "** expected:" + print expected_result + print "** received:" + print result + + + filename = "test.txt" + out_file = open (filename, "w") + out_file.write (test_data) + out_file.close () + + in_file = TextFile (filename, strip_comments=0, skip_blanks=0, + lstrip_ws=0, rstrip_ws=0) + test_input (1, "no processing", in_file, result1) + + in_file = TextFile (filename, strip_comments=1, skip_blanks=0, + lstrip_ws=0, rstrip_ws=0) + test_input (2, "strip comments", in_file, result2) + + in_file = TextFile (filename, strip_comments=0, skip_blanks=1, + lstrip_ws=0, rstrip_ws=0) + test_input (3, "strip blanks", in_file, result3) + + in_file = TextFile (filename) + test_input (4, "default processing", in_file, result4) + + in_file = TextFile (filename, strip_comments=1, skip_blanks=1, + join_lines=1, rstrip_ws=1) + test_input (5, "full processing", in_file, result5) + + os.remove (filename) +