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.
diff --git a/Lib/distutils/text_file.py b/Lib/distutils/text_file.py
new file mode 100644
index 0000000..9fff941
--- /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)
+