This module 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.
#is your comment character), skip blank lines, join adjacent lines by escaping the newline (ie. backslash at end of line), strip leading and/or trailing whitespace. All of these are optional and independently controllable.
The class provides a warn() method so you can generate warning messages that report physical line number, even if the logical line in question spans multiple physical lines. Also provides unreadline() for implementing line-at-a-time lookahead.
TextFile instances are create with either filename, file,
or both. RuntimeError is raised if both are
filename should be a string, and file a file object (or
something that provides readline() and close()
methods). It is recommended that you supply at least filename,
so that TextFile can include it in warning messages. If
file is not supplied, TextFile creates its own using the
open() built-in function.
The options are all boolean, and affect the values returned by readline()
|strip from "#" to end-of-line, as well as any whitespace leading up to the "#"--unless it is escaped by a backslash||true|
|strip leading whitespace from each line before returning it||false|
|strip trailing whitespace (including line terminator!) from each line before returning it.||true|
|skip lines that are empty *after* stripping comments and whitespace. (If both lstrip_ws and rstrip_ws are false, then some lines may consist of solely whitespace: these will *not* be skipped, even if skip_blanks is true.)||true|
|if a backslash is the last non-newline character on a line after stripping comments and whitespace, join the following line to it to form one logical line; if N consecutive lines end with a backslash, then N+1 physical lines will be joined to form one logical line.||false|
|strip leading whitespace from lines that are joined to their predecessor; only matters if "(join_lines and not lstrip_ws)"||false|
Note that since rstrip_ws can strip the trailing newline, the
semantics of readline() must differ from those of the builtin file
object's readline() method! In particular, readline()
None for end-of-file: an empty string might just be a
blank line (or an all-whitespace line), if rstrip_ws is true
but skip_blanks is not.
Noneon end-of-file, since the empty string can occur if rstrip_ws is true but strip_blanks is not.
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