#1682942: add some ConfigParser features: alternate delimiters, alternate...

#1682942: add some ConfigParser features: alternate delimiters, alternate comments, empty lines in values.  Also enhance the docs with more examples and mention SafeConfigParser before ConfigParser.  Patch by Lukas Langa, review by myself, Eric and Ezio.

Doc/library/configparser.rst

@@ -15,105 +15,168 @@
    single: ini file
    single: Windows ini file
 
-This module defines the class :class:`ConfigParser`.   The :class:`ConfigParser`
-class implements a basic configuration file parser language which provides a
-structure similar to what you would find on Microsoft Windows INI files.  You
-can use this to write Python programs which can be customized by end users
-easily.
+This module provides the classes :class:`RawConfigParser` and
+:class:`SafeConfigParser`.  They implement a basic configuration file parser
+language which provides a structure similar to what you would find in Microsoft
+Windows INI files.  You can use this to write Python programs which can be
+customized by end users easily.
 
 .. note::
 
    This library does *not* interpret or write the value-type prefixes used in
    the Windows Registry extended version of INI syntax.
 
-The configuration file consists of sections, led by a ``[section]`` header and
-followed by ``name: value`` entries, with continuations in the style of
-:rfc:`822` (see section 3.1.1, "LONG HEADER FIELDS"); ``name=value`` is also
-accepted.  Note that leading whitespace is removed from values. The optional
-values can contain format strings which refer to other values in the same
-section, or values in a special ``DEFAULT`` section.  Additional defaults can be
-provided on initialization and retrieval.  Lines beginning with ``'#'`` or
-``';'`` are ignored and may be used to provide comments.
+A configuration file consists of sections, each led by a ``[section]`` header,
+followed by name/value entries separated by a specific string (``=`` or ``:`` by
+default).  Note that leading whitespace is removed from values.  Values can be
+ommitted, in which case the key/value delimiter may also be left out.  Values
+can also span multiple lines, as long as they are indented deeper than the first
+line of the value.  Depending on the parser's mode, blank lines may be treated
+as parts of multiline values or ignored.
+
+Configuration files may include comments, prefixed by specific characters (``#``
+and ``;`` by default).  Comments may appear on their own in an otherwise empty
+line, or may be entered in lines holding values or spection names.  In the
+latter case, they need to be preceded by a whitespace character to be recognized
+as a comment.  (For backwards compatibility, by default only ``;`` starts an
+inline comment, while ``#`` does not.)
+
+On top of the core functionality, :class:`SafeConfigParser` supports
+interpolation.  This means values can contain format strings which refer to
+other values in the same section, or values in a special ``DEFAULT`` section.
+Additional defaults can be provided on initialization and retrieval.
 
 For example::
 
-   [My Section]
-   foodir: %(dir)s/whatever
-   dir=frob
-   long: this value continues
-      in the next line
-
-would resolve the ``%(dir)s`` to the value of ``dir`` (``frob`` in this case).
-All reference expansions are done on demand.
-
-Default values can be specified by passing them into the :class:`ConfigParser`
-constructor as a dictionary.  Additional defaults  may be passed into the
-:meth:`get` method which will override all others.
-
-Sections are normally stored in a built-in dictionary. An alternative dictionary
-type can be passed to the :class:`ConfigParser` constructor. For example, if a
-dictionary type is passed that sorts its keys, the sections will be sorted on
-write-back, as will be the keys within each section.
-
-
-.. class:: RawConfigParser(defaults=None, dict_type=collections.OrderedDict,
-                           allow_no_value=False)
+   [Paths]
+   home_dir: /Users
+   my_dir: %(home_dir)s/lumberjack
+   my_pictures: %(my_dir)s/Pictures
+
+   [Multiline Values]
+   chorus: I'm a lumberjack, and I'm okay
+      I sleep all night and I work all day
+
+   [No Values]
+   key_without_value
+   empty string value here =
+
+   [You can use comments] ; after a useful line
+   ; in an empty line
+   after: a_value ; here's another comment
+   inside: a         ;comment
+           multiline ;comment
+           value!    ;comment
+
+      [Sections Can Be Indented]
+         can_values_be_as_well = True
+         does_that_mean_anything_special = False
+         purpose = formatting for readability
+         multiline_values = are
+            handled just fine as
+            long as they are indented
+            deeper than the first line
+            of a value
+         # Did I mention we can indent comments, too?
+
+
+In the example above, :class:`SafeConfigParser` would resolve ``%(home_dir)s``
+to the value of ``home_dir`` (``/Users`` in this case).  ``%(my_dir)s`` in
+effect would resolve to ``/Users/lumberjack``.  All interpolations are done on
+demand so keys used in the chain of references do not have to be specified in
+any specific order in the configuration file.
+
+:class:`RawConfigParser` would simply return ``%(my_dir)s/Pictures`` as the
+value of ``my_pictures`` and ``%(home_dir)s/lumberjack`` as the value of
+``my_dir``.  Other features presented in the example are handled in the same
+manner by both parsers.
+
+Default values can be specified by passing them as a dictionary when
+constructing the :class:`SafeConfigParser`.  Additional defaults may be passed
+to the :meth:`get` method which will override all others.
+
+Sections are normally stored in an :class:`collections.OrderedDict` which
+maintains the order of all keys.  An alternative dictionary type can be passed
+to the :meth:`__init__` method.  For example, if a dictionary type is passed
+that sorts its keys, the sections will be sorted on write-back, as will be the
+keys within each section.
+
+
+.. class:: RawConfigParser(defaults=None, dict_type=collections.OrderedDict, delimiters=('=', ':'), comment_prefixes=_COMPATIBLE, empty_lines_in_values=True, allow_no_value=False)
 
    The basic configuration object.  When *defaults* is given, it is initialized
-   into the dictionary of intrinsic defaults.  When *dict_type* is given, it will
-   be used to create the dictionary objects for the list of sections, for the
-   options within a section, and for the default values.  When *allow_no_value*
-   is true (default: ``False``), options without values are accepted; the value
+   into the dictionary of intrinsic defaults.  When *dict_type* is given, it
+   will be used to create the dictionary objects for the list of sections, for
+   the options within a section, and for the default values.
+
+   When *delimiters* is given, it will be used as the set of substrings that
+   divide keys from values.  When *comment_prefixes* is given, it will be used
+   as the set of substrings that prefix comments in a line, both for the whole
+   line and inline comments.  For backwards compatibility, the default value for
+   *comment_prefixes* is a special value that indicates that ``;`` and ``#`` can
+   start whole line comments while only ``;`` can start inline comments.
+
+   When *empty_lines_in_values* is ``False`` (default: ``True``), each empty
+   line marks the end of an option.  Otherwise, internal empty lines of a
+   multiline option are kept as part of the value.  When *allow_no_value* is
+   true (default: ``False``), options without values are accepted; the value
    presented for these is ``None``.
 
-   This class does not
-   support the magical interpolation behavior.
+   This class does not support the magical interpolation behavior.
 
    .. versionchanged:: 3.1
       The default *dict_type* is :class:`collections.OrderedDict`.
 
    .. versionchanged:: 3.2
-      *allow_no_value* was added.
+      *delimiters*, *comment_prefixes*, *empty_lines_in_values* and
+      *allow_no_value* were added.
 
 
-.. class:: ConfigParser(defaults=None, dict_type=collections.OrderedDict,
-                        allow_no_value=False)
+.. class:: SafeConfigParser(defaults=None, dict_type=collections.OrderedDict, delimiters=('=', ':'), comment_prefixes=('#', ';'), empty_lines_in_values=True, allow_no_value=False)
 
-   Derived class of :class:`RawConfigParser` that implements the magical
-   interpolation feature and adds optional arguments to the :meth:`get` and
-   :meth:`items` methods.  The values in *defaults* must be appropriate for the
-   ``%()s`` string interpolation.  Note that *__name__* is an intrinsic default;
-   its value is the section name, and will override any value provided in
-   *defaults*.
+   Derived class of :class:`ConfigParser` that implements a sane variant of the
+   magical interpolation feature.  This implementation is more predictable as it
+   validates the interpolation syntax used within a configuration file.  This
+   class also enables escaping the interpolation character (e.g. a key can have
+   ``%`` as part of the value by specifying ``%%`` in the file).
 
-   All option names used in interpolation will be passed through the
-   :meth:`optionxform` method just like any other option name reference.  For
-   example, using the default implementation of :meth:`optionxform` (which converts
-   option names to lower case), the values ``foo %(bar)s`` and ``foo %(BAR)s`` are
-   equivalent.
+   Applications that don't require interpolation should use
+   :class:`RawConfigParser`, otherwise :class:`SafeConfigParser` is the best
+   option.
 
    .. versionchanged:: 3.1
       The default *dict_type* is :class:`collections.OrderedDict`.
 
    .. versionchanged:: 3.2
-      *allow_no_value* was added.
+      *delimiters*, *comment_prefixes*, *empty_lines_in_values* and
+      *allow_no_value* were added.
+
 
+.. class:: ConfigParser(defaults=None, dict_type=collections.OrderedDict, delimiters=('=', ':'), comment_prefixes=('#', ';'), empty_lines_in_values=True, allow_no_value=False)
+
+   Derived class of :class:`RawConfigParser` that implements the magical
+   interpolation feature and adds optional arguments to the :meth:`get` and
+   :meth:`items` methods.
 
-.. class:: SafeConfigParser(defaults=None, dict_type=collections.OrderedDict,
-                            allow_no_value=False)
+   :class:`SafeConfigParser` is generally recommended over this class if you
+   need interpolation.
 
-   Derived class of :class:`ConfigParser` that implements a more-sane variant of
-   the magical interpolation feature.  This implementation is more predictable as
-   well. New applications should prefer this version if they don't need to be
-   compatible with older versions of Python.
+   The values in *defaults* must be appropriate for the ``%()s`` string
+   interpolation.  Note that *__name__* is an intrinsic default; its value is
+   the section name, and will override any value provided in *defaults*.
 
-   .. XXX Need to explain what's safer/more predictable about it.
+   All option names used in interpolation will be passed through the
+   :meth:`optionxform` method just like any other option name reference.  For
+   example, using the default implementation of :meth:`optionxform` (which
+   converts option names to lower case), the values ``foo %(bar)s`` and ``foo
+   %(BAR)s`` are equivalent.
 
    .. versionchanged:: 3.1
       The default *dict_type* is :class:`collections.OrderedDict`.
 
    .. versionchanged:: 3.2
-      *allow_no_value* was added.
+      *delimiters*, *comment_prefixes*, *empty_lines_in_values* and
+      *allow_no_value* were added.
 
 
 .. exception:: NoSectionError
@@ -295,11 +358,13 @@ RawConfigParser Objects
    interpolation and output to files) can only be achieved using string values.
 
 
-.. method:: RawConfigParser.write(fileobject)
+.. method:: RawConfigParser.write(fileobject, space_around_delimiters=True)
 
    Write a representation of the configuration to the specified file object,
    which must be opened in text mode (accepting strings).  This representation
-   can be parsed by a future :meth:`read` call.
+   can be parsed by a future :meth:`read` call. If ``space_around_delimiters``
+   is ``True`` (the default), delimiters between keys and values are surrounded
+   by spaces.
 
 
 .. method:: RawConfigParser.remove_option(section, option)
@@ -342,21 +407,24 @@ ConfigParser Objects
 --------------------
 
 The :class:`ConfigParser` class extends some methods of the
-:class:`RawConfigParser` interface, adding some optional arguments.
+:class:`RawConfigParser` interface, adding some optional arguments. Whenever you
+can, consider using :class:`SafeConfigParser` which adds validation and escaping
+for the interpolation.
 
 
 .. method:: ConfigParser.get(section, option, raw=False, vars=None)
 
-   Get an *option* value for the named *section*.  All the ``'%'`` interpolations
-   are expanded in the return values, based on the defaults passed into the
-   constructor, as well as the options *vars* provided, unless the *raw* argument
-   is true.
+   Get an *option* value for the named *section*.  All the ``'%'``
+   interpolations are expanded in the return values, based on the defaults
+   passed into the :meth:`__init__` method, as well as the options *vars*
+   provided, unless the *raw* argument is true.
 
 
 .. method:: ConfigParser.items(section, raw=False, vars=None)
 
-   Return a list of ``(name, value)`` pairs for each option in the given *section*.
-   Optional arguments have the same meaning as for the :meth:`get` method.
+   Return a list of ``(name, value)`` pairs for each option in the given
+   *section*.  Optional arguments have the same meaning as for the :meth:`get`
+   method.
 
 
 .. _safeconfigparser-objects:
@@ -466,8 +534,8 @@ The function ``opt_move`` below can be used to move options between sections::
 
 Some configuration files are known to include settings without values, but which
 otherwise conform to the syntax supported by :mod:`configparser`.  The
-*allow_no_value* parameter to the constructor can be used to indicate that such
-values should be accepted:
+*allow_no_value* parameter to the :meth:`__init__` method can be used to
+indicate that such values should be accepted:
 
 .. doctest::
 
@@ -481,7 +549,7 @@ values should be accepted:
    ...   skip-external-locking
    ...   old_passwords = 1
    ...   skip-bdb
-   ... skip-innodb
+   ...   skip-innodb # we don't need ACID today
    ... """
    >>> config = configparser.RawConfigParser(allow_no_value=True)
    >>> config.readfp(io.BytesIO(sample_config))

Lib/configparser.py

 """Configuration file parser.
 
-A setup file consists of sections, lead by a "[section]" header,
+A configuration file consists of sections, lead by a "[section]" header,
 and followed by "name: value" entries, with continuations and such in
 the style of RFC 822.
 
@@ -24,67 +24,88 @@ ConfigParser -- responsible for parsing a list of
 
     methods:
 
-    __init__(defaults=None)
-        create the parser and specify a dictionary of intrinsic defaults.  The
-        keys must be strings, the values must be appropriate for %()s string
-        interpolation.  Note that `__name__' is always an intrinsic default;
-        its value is the section's name.
+    __init__(defaults=None, dict_type=_default_dict,
+             delimiters=('=', ':'), comment_prefixes=('#', ';'),
+             empty_lines_in_values=True, allow_no_value=False):
+        Create the parser. When `defaults' is given, it is initialized into the
+        dictionary or intrinsic defaults. The keys must be strings, the values
+        must be appropriate for %()s string interpolation.  Note that `__name__'
+        is always an intrinsic default; its value is the section's name.
+
+        When `dict_type' is given, it will be used to create the dictionary
+        objects for the list of sections, for the options within a section, and
+        for the default values.
+
+        When `delimiters' is given, it will be used as the set of substrings
+        that divide keys from values.
+
+        When `comment_prefixes' is given, it will be used as the set of
+        substrings that prefix comments in a line.
+
+        When `empty_lines_in_values' is False (default: True), each empty line
+        marks the end of an option. Otherwise, internal empty lines of
+        a multiline option are kept as part of the value.
+
+        When `allow_no_value' is True (default: False), options without
+        values are accepted; the value presented for these is None.
 
     sections()
-        return all the configuration section names, sans DEFAULT
+        Return all the configuration section names, sans DEFAULT.
 
     has_section(section)
-        return whether the given section exists
+        Return whether the given section exists.
 
     has_option(section, option)
-        return whether the given option exists in the given section
+        Return whether the given option exists in the given section.
 
     options(section)
-        return list of configuration options for the named section
+        Return list of configuration options for the named section.
 
     read(filenames)
-        read and parse the list of named configuration files, given by
+        Read and parse the list of named configuration files, given by
         name.  A single filename is also allowed.  Non-existing files
         are ignored.  Return list of successfully read files.
 
     readfp(fp, filename=None)
-        read and parse one configuration file, given as a file object.
+        Read and parse one configuration file, given as a file object.
         The filename defaults to fp.name; it is only used in error
         messages (if fp has no `name' attribute, the string `<???>' is used).
 
     get(section, option, raw=False, vars=None)
-        return a string value for the named option.  All % interpolations are
+        Return a string value for the named option.  All % interpolations are
         expanded in the return values, based on the defaults passed into the
         constructor and the DEFAULT section.  Additional substitutions may be
         provided using the `vars' argument, which must be a dictionary whose
         contents override any pre-existing defaults.
 
     getint(section, options)
-        like get(), but convert value to an integer
+        Like get(), but convert value to an integer.
 
     getfloat(section, options)
-        like get(), but convert value to a float
+        Like get(), but convert value to a float.
 
     getboolean(section, options)
-        like get(), but convert value to a boolean (currently case
+        Like get(), but convert value to a boolean (currently case
         insensitively defined as 0, false, no, off for False, and 1, true,
         yes, on for True).  Returns False or True.
 
     items(section, raw=False, vars=None)
-        return a list of tuples with (name, value) for each option
+        Return a list of tuples with (name, value) for each option
         in the section.
 
     remove_section(section)
-        remove the given file section and all its options
+        Remove the given file section and all its options.
 
     remove_option(section, option)
-        remove the given option from the given section
+        Remove the given option from the given section.
 
     set(section, option, value)
-        set the given option
+        Set the given option.
 
-    write(fp)
-        write the configuration state in .ini format
+    write(fp, space_around_delimiters=True)
+        Write the configuration state in .ini format. If
+        `space_around_delimiters' is True (the default), delimiters
+        between keys and values are surrounded by spaces.
 """
 
 try:
@@ -94,6 +115,7 @@ except ImportError:
     _default_dict = dict
 
 import re
+import sys
 
 __all__ = ["NoSectionError", "DuplicateSectionError", "NoOptionError",
            "InterpolationError", "InterpolationDepthError",
@@ -114,17 +136,19 @@ class Error(Exception):
 
     def _get_message(self):
         """Getter for 'message'; needed only to override deprecation in
-        BaseException."""
+        BaseException.
+        """
         return self.__message
 
     def _set_message(self, value):
         """Setter for 'message'; needed only to override deprecation in
-        BaseException."""
+        BaseException.
+        """
         self.__message = value
 
     # BaseException.message has been deprecated since Python 2.6.  To prevent
-    # DeprecationWarning from popping up over this pre-existing attribute, use
-    # a new property that takes lookup precedence.
+    # DeprecationWarning from popping up over this pre-existing attribute, use a
+    # new property that takes lookup precedence.
     message = property(_get_message, _set_message)
 
     def __init__(self, msg=''):
@@ -136,6 +160,7 @@ class Error(Exception):
 
     __str__ = __repr__
 
+
 class NoSectionError(Error):
     """Raised when no section matches a requested option."""
 
@@ -144,6 +169,7 @@ class NoSectionError(Error):
         self.section = section
         self.args = (section, )
 
+
 class DuplicateSectionError(Error):
     """Raised when a section is multiply-created."""
 
@@ -152,6 +178,7 @@ class DuplicateSectionError(Error):
         self.section = section
         self.args = (section, )
 
+
 class NoOptionError(Error):
     """A requested option was not found."""
 
@@ -162,6 +189,7 @@ class NoOptionError(Error):
         self.section = section
         self.args = (option, section)
 
+
 class InterpolationError(Error):
     """Base class for interpolation-related exceptions."""
 
@@ -171,6 +199,7 @@ class InterpolationError(Error):
         self.section = section
         self.args = (option, section, msg)
 
+
 class InterpolationMissingOptionError(InterpolationError):
     """A string substitution required a setting which was not available."""
 
@@ -185,10 +214,12 @@ class InterpolationMissingOptionError(InterpolationError):
         self.reference = reference
         self.args = (option, section, rawval, reference)
 
+
 class InterpolationSyntaxError(InterpolationError):
     """Raised when the source text into which substitutions are made
     does not conform to the required syntax."""
 
+
 class InterpolationDepthError(InterpolationError):
     """Raised when substitutions are nested too deeply."""
 
@@ -201,6 +232,7 @@ class InterpolationDepthError(InterpolationError):
         InterpolationError.__init__(self, option, section, msg)
         self.args = (option, section, rawval)
 
+
 class ParsingError(Error):
     """Raised when a configuration file does not follow legal syntax."""
 
@@ -214,6 +246,7 @@ class ParsingError(Error):
         self.errors.append((lineno, line))
         self.message += '\n\t[line %2d]: %s' % (lineno, line)
 
+
 class MissingSectionHeaderError(ParsingError):
     """Raised when a key-value pair is found before any section header."""
 
@@ -227,19 +260,74 @@ class MissingSectionHeaderError(ParsingError):
         self.line = line
         self.args = (filename, lineno, line)
 
+
 class RawConfigParser:
+    """ConfigParser that does not do interpolation."""
+
+    # Regular expressions for parsing section headers and options
+    _SECT_TMPL = r"""
+        \[                                 # [
+        (?P<header>[^]]+)                  # very permissive!
+        \]                                 # ]
+        """
+    _OPT_TMPL = r"""
+        (?P<option>.*?)                    # very permissive!
+        \s*(?P<vi>{delim})\s*              # any number of space/tab,
+                                           # followed by any of the
+                                           # allowed delimiters,
+                                           # followed by any space/tab
+        (?P<value>.*)$                     # everything up to eol
+        """
+    _OPT_NV_TMPL = r"""
+        (?P<option>.*?)                    # very permissive!
+        \s*(?:                             # any number of space/tab,
+        (?P<vi>{delim})\s*                 # optionally followed by
+                                           # any of the allowed
+                                           # delimiters, followed by any
+                                           # space/tab
+        (?P<value>.*))?$                   # everything up to eol
+        """
+
+    # Compiled regular expression for matching sections
+    SECTCRE = re.compile(_SECT_TMPL, re.VERBOSE)
+    # Compiled regular expression for matching options with typical separators
+    OPTCRE = re.compile(_OPT_TMPL.format(delim="=|:"), re.VERBOSE)
+    # Compiled regular expression for matching options with optional values
+    # delimited using typical separators
+    OPTCRE_NV = re.compile(_OPT_NV_TMPL.format(delim="=|:"), re.VERBOSE)
+    # Compiled regular expression for matching leading whitespace in a line
+    NONSPACECRE = re.compile(r"\S")
+    # Select backwards-compatible inline comment character behavior
+    # (; and # are comments at the start of a line, but ; only inline)
+    _COMPATIBLE = object()
+
     def __init__(self, defaults=None, dict_type=_default_dict,
-                 allow_no_value=False):
+                 delimiters=('=', ':'), comment_prefixes=_COMPATIBLE,
+                 empty_lines_in_values=True, allow_no_value=False):
         self._dict = dict_type
         self._sections = self._dict()
         self._defaults = self._dict()
-        if allow_no_value:
-            self._optcre = self.OPTCRE_NV
-        else:
-            self._optcre = self.OPTCRE
         if defaults:
             for key, value in defaults.items():
                 self._defaults[self.optionxform(key)] = value
+        self._delimiters = tuple(delimiters)
+        if delimiters == ('=', ':'):
+            self._optcre = self.OPTCRE_NV if allow_no_value else self.OPTCRE
+        else:
+            delim = "|".join(re.escape(d) for d in delimiters)
+            if allow_no_value:
+                self._optcre = re.compile(self._OPT_NV_TMPL.format(delim=delim),
+                                          re.VERBOSE)
+            else:
+                self._optcre = re.compile(self._OPT_TMPL.format(delim=delim),
+                                          re.VERBOSE)
+        if comment_prefixes is self._COMPATIBLE:
+            self._startonly_comment_prefixes = ('#',)
+            self._comment_prefixes = (';',)
+        else:
+            self._startonly_comment_prefixes = ()
+            self._comment_prefixes = tuple(comment_prefixes or ())
+        self._empty_lines_in_values = empty_lines_in_values
 
     def defaults(self):
         return self._defaults
@@ -313,7 +401,6 @@ class RawConfigParser:
         second argument is the `filename', which if not given, is
         taken from fp.name.  If fp has no `name' attribute, `<???>' is
         used.
-
         """
         if filename is None:
             try:
@@ -374,6 +461,7 @@ class RawConfigParser:
 
     def has_option(self, section, option):
         """Check for the existence of a given option in a given section."""
+
         if not section or section == DEFAULTSECT:
             option = self.optionxform(option)
             return option in self._defaults
@@ -386,6 +474,7 @@ class RawConfigParser:
 
     def set(self, section, option, value=None):
         """Set an option."""
+
         if not section or section == DEFAULTSECT:
             sectdict = self._defaults
         else:
@@ -395,21 +484,33 @@ class RawConfigParser:
                 raise NoSectionError(section)
         sectdict[self.optionxform(option)] = value
 
-    def write(self, fp):
-        """Write an .ini-format representation of the configuration state."""
+    def write(self, fp, space_around_delimiters=True):
+        """Write an .ini-format representation of the configuration state.
+
+        If `space_around_delimiters' is True (the default), delimiters
+        between keys and values are surrounded by spaces.
+        """
+        if space_around_delimiters:
+            d = " {} ".format(self._delimiters[0])
+        else:
+            d = self._delimiters[0]
         if self._defaults:
-            fp.write("[%s]\n" % DEFAULTSECT)
-            for (key, value) in self._defaults.items():
-                fp.write("%s = %s\n" % (key, str(value).replace('\n', '\n\t')))
-            fp.write("\n")
+            self._write_section(fp, DEFAULTSECT, self._defaults.items(), d)
         for section in self._sections:
-            fp.write("[%s]\n" % section)
-            for (key, value) in self._sections[section].items():
+            self._write_section(fp, section,
+                                self._sections[section].items(), d)
+
+    def _write_section(self, fp, section_name, section_items, delimiter):
+        """Write a single section to the specified `fp'."""
+        fp.write("[{}]\n".format(section_name))
+        for key, value in section_items:
             if key == "__name__":
                 continue
             if value is not None:
-                    key = " = ".join((key, str(value).replace('\n', '\n\t')))
-                fp.write("%s\n" % (key))
+                value = delimiter + str(value).replace('\n', '\n\t')
+            else:
+                value = ""
+            fp.write("{}{}\n".format(key, value))
         fp.write("\n")
 
     def remove_option(self, section, option):
@@ -434,66 +535,63 @@ class RawConfigParser:
             del self._sections[section]
         return existed
 
-    #
-    # Regular expressions for parsing section headers and options.
-    #
-    SECTCRE = re.compile(
-        r'\['                                 # [
-        r'(?P<header>[^]]+)'                  # very permissive!
-        r'\]'                                 # ]
-        )
-    OPTCRE = re.compile(
-        r'(?P<option>[^:=\s][^:=]*)'          # very permissive!
-        r'\s*(?P<vi>[:=])\s*'                 # any number of space/tab,
-                                              # followed by separator
-                                              # (either : or =), followed
-                                              # by any # space/tab
-        r'(?P<value>.*)$'                     # everything up to eol
-        )
-    OPTCRE_NV = re.compile(
-        r'(?P<option>[^:=\s][^:=]*)'          # very permissive!
-        r'\s*(?:'                             # any number of space/tab,
-        r'(?P<vi>[:=])\s*'                    # optionally followed by
-                                              # separator (either : or
-                                              # =), followed by any #
-                                              # space/tab
-        r'(?P<value>.*))?$'                   # everything up to eol
-        )
-
     def _read(self, fp, fpname):
-        """Parse a sectioned setup file.
-
-        The sections in setup file contains a title line at the top,
-        indicated by a name in square brackets (`[]'), plus key/value
-        options lines, indicated by `name: value' format lines.
-        Continuations are represented by an embedded newline then
-        leading whitespace.  Blank lines, lines beginning with a '#',
-        and just about everything else are ignored.
+        """Parse a sectioned configuration file.
+
+        Each section in a configuration file contains a header, indicated by a
+        name in square brackets (`[]'), plus key/value options, indicated by
+        `name' and `value' delimited with a specific substring (`=' or `:' by
+        default).
+
+        Values can span multiple lines, as long as they are indented deeper than
+        the first line of the value. Depending on the parser's mode, blank lines
+        may be treated as parts of multiline values or ignored.
+
+        Configuration files may include comments, prefixed by specific
+        characters (`#' and `;' by default). Comments may appear on their own in
+        an otherwise empty line or may be entered in lines holding values or
+        section names.
         """
         cursect = None                        # None, or a dictionary
         optname = None
         lineno = 0
+        indent_level = 0
         e = None                              # None, or an exception
-        while True:
-            line = fp.readline()
-            if not line:
+        for lineno, line in enumerate(fp, start=1):
+            # strip prefix-only comments
+            comment_start = None
+            for prefix in self._startonly_comment_prefixes:
+                if line.strip().startswith(prefix):
+                    comment_start = 0
                     break
-            lineno = lineno + 1
-            # comment or blank line?
-            if line.strip() == '' or line[0] in '#;':
-                continue
-            if line.split(None, 1)[0].lower() == 'rem' and line[0] in "rR":
-                # no leading whitespace
+            # strip inline comments
+            for prefix in self._comment_prefixes:
+                index = line.find(prefix)
+                if index == 0 or (index > 0 and line[index-1].isspace()):
+                    comment_start = index
+                    break
+            value = line[:comment_start].strip()
+            if not value:
+                if self._empty_lines_in_values and comment_start is None:
+                    # add empty line to the value, but only if there was no
+                    # comment on the line
+                    if cursect is not None and optname:
+                        cursect[optname].append('\n')
+                else:
+                    # empty line marks end of value
+                    indent_level = sys.maxsize
                 continue
             # continuation line?
-            if line[0].isspace() and cursect is not None and optname:
-                value = line.strip()
-                if value:
+            first_nonspace = self.NONSPACECRE.search(line)
+            cur_indent_level = first_nonspace.start() if first_nonspace else 0
+            if (cursect is not None and optname and
+                cur_indent_level > indent_level):
                 cursect[optname].append(value)
             # a section header or option header?
             else:
+                indent_level = cur_indent_level
                 # is it a section header?
-                mo = self.SECTCRE.match(line)
+                mo = self.SECTCRE.match(value)
                 if mo:
                     sectname = mo.group('header')
                     if sectname in self._sections:
@@ -511,19 +609,15 @@ class RawConfigParser:
                     raise MissingSectionHeaderError(fpname, lineno, line)
                 # an option line?
                 else:
-                    mo = self._optcre.match(line)
+                    mo = self._optcre.match(value)
                     if mo:
                         optname, vi, optval = mo.group('option', 'vi', 'value')
+                        if not optname:
+                            e = self._handle_error(e, fpname, lineno, line)
                         optname = self.optionxform(optname.rstrip())
                         # This check is fine because the OPTCRE cannot
                         # match if it would set optval to None
                         if optval is not None:
-                            if vi in ('=', ':') and ';' in optval:
-                                # ';' is a comment delimiter only if it follows
-                                # a spacing character
-                                pos = optval.find(';')
-                                if pos != -1 and optval[pos-1].isspace():
-                                    optval = optval[:pos]
                             optval = optval.strip()
                             # allow empty values
                             if optval == '""':
@@ -537,22 +631,31 @@ class RawConfigParser:
                         # exception but keep going. the exception will be
                         # raised at the end of the file and will contain a
                         # list of all bogus lines
-                        if not e:
-                            e = ParsingError(fpname)
-                        e.append(lineno, repr(line))
+                        e = self._handle_error(e, fpname, lineno, line)
         # if any parsing errors occurred, raise an exception
         if e:
             raise e
+        self._join_multiline_values()
 
-        # join the multi-line values collected while reading
+    def _join_multiline_values(self):
         all_sections = [self._defaults]
         all_sections.extend(self._sections.values())
         for options in all_sections:
             for name, val in options.items():
                 if isinstance(val, list):
+                    if val[-1] == '\n':
+                        val = val[:-1]
                     options[name] = '\n'.join(val)
 
+    def _handle_error(self, exc, fpname, lineno, line):
+        if not exc:
+            exc = ParsingError(fpname)
+        exc.append(lineno, repr(line))
+        return exc
+
+
 class ConfigParser(RawConfigParser):
+    """ConfigParser implementing interpolation."""
 
     def get(self, section, option, raw=False, vars=None):
         """Get an option value for a given section.
@@ -648,6 +751,7 @@ class ConfigParser(RawConfigParser):
 
 
 class SafeConfigParser(ConfigParser):
+    """ConfigParser implementing sane interpolation."""
 
     def _interpolate(self, section, option, rawval, vars):
         # do the string interpolation

Lib/test/test_cfgparser.py

@@ -3,6 +3,7 @@ import configparser
 import io
 import os
 import unittest
+import textwrap
 
 from test import support
 
@@ -23,15 +24,26 @@ class SortedDict(collections.UserDict):
     def itervalues(self): return iter(self.values())
 
 
-class TestCaseBase(unittest.TestCase):
+class CfgParserTestCaseClass(unittest.TestCase):
     allow_no_value = False
+    delimiters = ('=', ':')
+    comment_prefixes = (';', '#')
+    empty_lines_in_values = True
+    dict_type = configparser._default_dict
 
     def newconfig(self, defaults=None):
+        arguments = dict(
+            allow_no_value=self.allow_no_value,
+            delimiters=self.delimiters,
+            comment_prefixes=self.comment_prefixes,
+            empty_lines_in_values=self.empty_lines_in_values,
+            dict_type=self.dict_type,
+        )
         if defaults is None:
-            self.cf = self.config_class(allow_no_value=self.allow_no_value)
+            self.cf = self.config_class(**arguments)
         else:
             self.cf = self.config_class(defaults,
-                                        allow_no_value=self.allow_no_value)
+                                        **arguments)
         return self.cf
 
     def fromstring(self, string, defaults=None):
@@ -40,27 +52,33 @@ class TestCaseBase(unittest.TestCase):
         cf.readfp(sio)
         return cf
 
+class BasicTestCase(CfgParserTestCaseClass):
+
     def test_basic(self):
-        config_string = (
-            "[Foo Bar]\n"
-            "foo=bar\n"
-            "[Spacey Bar]\n"
-            "foo = bar\n"
-            "[Commented Bar]\n"
-            "foo: bar ; comment\n"
-            "[Long Line]\n"
-            "foo: this line is much, much longer than my editor\n"
-            "   likes it.\n"
-            "[Section\\with$weird%characters[\t]\n"
-            "[Internationalized Stuff]\n"
-            "foo[bg]: Bulgarian\n"
-            "foo=Default\n"
-            "foo[en]=English\n"
-            "foo[de]=Deutsch\n"
-            "[Spaces]\n"
-            "key with spaces : value\n"
-            "another with spaces = splat!\n"
-            )
+        config_string = """\
+[Foo Bar]
+foo{0[0]}bar
+[Spacey Bar]
+foo {0[0]} bar
+[Spacey Bar From The Beginning]
+  foo {0[0]} bar
+  baz {0[0]} qwe
+[Commented Bar]
+foo{0[1]} bar {1[1]} comment
+baz{0[0]}qwe {1[0]}another one
+[Long Line]
+foo{0[1]} this line is much, much longer than my editor
+   likes it.
+[Section\\with$weird%characters[\t]
+[Internationalized Stuff]
+foo[bg]{0[1]} Bulgarian
+foo{0[0]}Default
+foo[en]{0[0]}English
+foo[de]{0[0]}Deutsch
+[Spaces]
+key with spaces {0[1]} value
+another with spaces {0[0]} splat!
+""".format(self.delimiters, self.comment_prefixes)
         if self.allow_no_value:
             config_string += (
                 "[NoValue]\n"
@@ -70,13 +88,14 @@ class TestCaseBase(unittest.TestCase):
         cf = self.fromstring(config_string)
         L = cf.sections()
         L.sort()
-        E = [r'Commented Bar',
-             r'Foo Bar',
-             r'Internationalized Stuff',
-             r'Long Line',
-             r'Section\with$weird%characters[' '\t',
-             r'Spaces',
-             r'Spacey Bar',
+        E = ['Commented Bar',
+             'Foo Bar',
+             'Internationalized Stuff',
+             'Long Line',
+             'Section\\with$weird%characters[\t',
+             'Spaces',
+             'Spacey Bar',
+             'Spacey Bar From The Beginning',
              ]
         if self.allow_no_value:
             E.append(r'NoValue')
@@ -89,7 +108,10 @@ class TestCaseBase(unittest.TestCase):
         # http://www.python.org/sf/583248
         eq(cf.get('Foo Bar', 'foo'), 'bar')
         eq(cf.get('Spacey Bar', 'foo'), 'bar')
+        eq(cf.get('Spacey Bar From The Beginning', 'foo'), 'bar')
+        eq(cf.get('Spacey Bar From The Beginning', 'baz'), 'qwe')
         eq(cf.get('Commented Bar', 'foo'), 'bar')
+        eq(cf.get('Commented Bar', 'baz'), 'qwe')
         eq(cf.get('Spaces', 'key with spaces'), 'value')
         eq(cf.get('Spaces', 'another with spaces'), 'splat!')
         if self.allow_no_value:
@@ -140,12 +162,14 @@ class TestCaseBase(unittest.TestCase):
 
         # SF bug #432369:
         cf = self.fromstring(
-            "[MySection]\nOption: first line\n\tsecond line\n")
+            "[MySection]\nOption{} first line\n\tsecond line\n".format(
+                self.delimiters[0]))
         eq(cf.options("MySection"), ["option"])
         eq(cf.get("MySection", "Option"), "first line\nsecond line")
 
         # SF bug #561822:
-        cf = self.fromstring("[section]\nnekey=nevalue\n",
+        cf = self.fromstring("[section]\n"
+                             "nekey{}nevalue\n".format(self.delimiters[0]),
                              defaults={"key":"value"})
         self.assertTrue(cf.has_option("section", "Key"))
 
@@ -162,18 +186,19 @@ class TestCaseBase(unittest.TestCase):
 
     def test_parse_errors(self):
         self.newconfig()
-        e = self.parse_error(configparser.ParsingError,
-                             "[Foo]\n  extra-spaces: splat\n")
-        self.assertEqual(e.args, ('<???>',))
         self.parse_error(configparser.ParsingError,
-                         "[Foo]\n  extra-spaces= splat\n")
-        self.parse_error(configparser.ParsingError,
-                         "[Foo]\n:value-without-option-name\n")
+                         "[Foo]\n"
+                         "{}val-without-opt-name\n".format(self.delimiters[0]))
         self.parse_error(configparser.ParsingError,
-                         "[Foo]\n=value-without-option-name\n")
+                         "[Foo]\n"
+                         "{}val-without-opt-name\n".format(self.delimiters[1]))
         e = self.parse_error(configparser.MissingSectionHeaderError,
                              "No Section!\n")
         self.assertEqual(e.args, ('<???>', 1, "No Section!\n"))
+        if not self.allow_no_value:
+            e = self.parse_error(configparser.ParsingError,
+                                "[Foo]\n  wrong-indent\n")
+            self.assertEqual(e.args, ('<???>',))
 
     def parse_error(self, exc, src):
         sio = io.StringIO(src)
@@ -188,9 +213,9 @@ class TestCaseBase(unittest.TestCase):
         self.assertFalse(cf.has_section("Foo"),
                          "new ConfigParser should have no acknowledged "
                          "sections")
-        with self.assertRaises(configparser.NoSectionError) as cm:
+        with self.assertRaises(configparser.NoSectionError):
             cf.options("Foo")
-        with self.assertRaises(configparser.NoSectionError) as cm:
+        with self.assertRaises(configparser.NoSectionError):
             cf.set("foo", "bar", "value")
         e = self.get_error(configparser.NoSectionError, "foo", "bar")
         self.assertEqual(e.args, ("foo",))
@@ -210,21 +235,21 @@ class TestCaseBase(unittest.TestCase):
     def test_boolean(self):
         cf = self.fromstring(
             "[BOOLTEST]\n"
-            "T1=1\n"
-            "T2=TRUE\n"
-            "T3=True\n"
-            "T4=oN\n"
-            "T5=yes\n"
-            "F1=0\n"
-            "F2=FALSE\n"
-            "F3=False\n"
-            "F4=oFF\n"
-            "F5=nO\n"
-            "E1=2\n"
-            "E2=foo\n"
-            "E3=-1\n"
-            "E4=0.1\n"
-            "E5=FALSE AND MORE"
+            "T1{equals}1\n"
+            "T2{equals}TRUE\n"
+            "T3{equals}True\n"
+            "T4{equals}oN\n"
+            "T5{equals}yes\n"
+            "F1{equals}0\n"
+            "F2{equals}FALSE\n"
+            "F3{equals}False\n"
+            "F4{equals}oFF\n"
+            "F5{equals}nO\n"
+            "E1{equals}2\n"
+            "E2{equals}foo\n"
+            "E3{equals}-1\n"
+            "E4{equals}0.1\n"
+            "E5{equals}FALSE AND MORE".format(equals=self.delimiters[0])
             )
         for x in range(1, 5):
             self.assertTrue(cf.getboolean('BOOLTEST', 't%d' % x))
@@ -242,11 +267,17 @@ class TestCaseBase(unittest.TestCase):
     def test_write(self):
         config_string = (
             "[Long Line]\n"
-            "foo: this line is much, much longer than my editor\n"
+            "foo{0[0]} this line is much, much longer than my editor\n"
             "   likes it.\n"
             "[DEFAULT]\n"
-            "foo: another very\n"
+            "foo{0[1]} another very\n"
             " long line\n"
+            "[Long Line - With Comments!]\n"
+            "test {0[1]} we        {comment} can\n"
+            "            also      {comment} place\n"
+            "            comments  {comment} in\n"
+            "            multiline {comment} values"
+            "\n".format(self.delimiters, comment=self.comment_prefixes[0])
             )
         if self.allow_no_value:
             config_string += (
@@ -259,13 +290,19 @@ class TestCaseBase(unittest.TestCase):
         cf.write(output)
         expect_string = (
             "[DEFAULT]\n"
-            "foo = another very\n"
+            "foo {equals} another very\n"
             "\tlong line\n"
             "\n"
             "[Long Line]\n"
-            "foo = this line is much, much longer than my editor\n"
+            "foo {equals} this line is much, much longer than my editor\n"
             "\tlikes it.\n"
             "\n"
+            "[Long Line - With Comments!]\n"
+            "test {equals} we\n"
+            "\talso\n"
+            "\tcomments\n"
+            "\tmultiline\n"
+            "\n".format(equals=self.delimiters[0])
             )
         if self.allow_no_value:
             expect_string += (
@@ -277,7 +314,7 @@ class TestCaseBase(unittest.TestCase):
 
     def test_set_string_types(self):
         cf = self.fromstring("[sect]\n"
-                             "option1=foo\n")
+                             "option1{eq}foo\n".format(eq=self.delimiters[0]))
         # Check that we don't get an exception when setting values in
         # an existing section using strings:
         class mystr(str):
@@ -290,6 +327,9 @@ class TestCaseBase(unittest.TestCase):
         cf.set("sect", "option2", "splat")
 
     def test_read_returns_file_list(self):
+        if self.delimiters[0] != '=':
+            # skip reading the file if we're using an incompatible format
+            return
         file1 = support.findfile("cfgparser.1")
         # check when we pass a mix of readable and non-readable files:
         cf = self.newconfig()
@@ -314,45 +354,45 @@ class TestCaseBase(unittest.TestCase):
     def get_interpolation_config(self):
         return self.fromstring(
             "[Foo]\n"
-            "bar=something %(with1)s interpolation (1 step)\n"
-            "bar9=something %(with9)s lots of interpolation (9 steps)\n"
-            "bar10=something %(with10)s lots of interpolation (10 steps)\n"
-            "bar11=something %(with11)s lots of interpolation (11 steps)\n"
-            "with11=%(with10)s\n"
-            "with10=%(with9)s\n"
-            "with9=%(with8)s\n"
-            "with8=%(With7)s\n"
-            "with7=%(WITH6)s\n"
-            "with6=%(with5)s\n"
-            "With5=%(with4)s\n"
-            "WITH4=%(with3)s\n"
-            "with3=%(with2)s\n"
-            "with2=%(with1)s\n"
-            "with1=with\n"
+            "bar{equals}something %(with1)s interpolation (1 step)\n"
+            "bar9{equals}something %(with9)s lots of interpolation (9 steps)\n"
+            "bar10{equals}something %(with10)s lots of interpolation (10 steps)\n"
+            "bar11{equals}something %(with11)s lots of interpolation (11 steps)\n"
+            "with11{equals}%(with10)s\n"
+            "with10{equals}%(with9)s\n"
+            "with9{equals}%(with8)s\n"
+            "with8{equals}%(With7)s\n"
+            "with7{equals}%(WITH6)s\n"
+            "with6{equals}%(with5)s\n"
+            "With5{equals}%(with4)s\n"
+            "WITH4{equals}%(with3)s\n"
+            "with3{equals}%(with2)s\n"
+            "with2{equals}%(with1)s\n"
+            "with1{equals}with\n"
             "\n"
             "[Mutual Recursion]\n"
-            "foo=%(bar)s\n"
-            "bar=%(foo)s\n"
+            "foo{equals}%(bar)s\n"
+            "bar{equals}%(foo)s\n"
             "\n"
             "[Interpolation Error]\n"
-            "name=%(reference)s\n",
+            "name{equals}%(reference)s\n".format(equals=self.delimiters[0]),
             # no definition for 'reference'
             defaults={"getname": "%(__name__)s"})
 
     def check_items_config(self, expected):
         cf = self.fromstring(
             "[section]\n"
-            "name = value\n"
-            "key: |%(name)s| \n"
-            "getdefault: |%(default)s|\n"
-            "getname: |%(__name__)s|",
+            "name {0[0]} value\n"
+            "key{0[1]} |%(name)s| \n"
+            "getdefault{0[1]} |%(default)s|\n"
+            "getname{0[1]} |%(__name__)s|".format(self.delimiters),
             defaults={"default": "<default>"})
         L = list(cf.items("section"))
         L.sort()
         self.assertEqual(L, expected)
 
 
-class ConfigParserTestCase(TestCaseBase):
+class ConfigParserTestCase(BasicTestCase):
     config_class = configparser.ConfigParser
 
     def test_interpolation(self):
@@ -414,7 +454,11 @@ class ConfigParserTestCase(TestCaseBase):
         self.assertRaises(ValueError, cf.get, 'non-string',
                           'string_with_interpolation', raw=False)
 
-class MultilineValuesTestCase(TestCaseBase):
+class ConfigParserTestCaseNonStandardDelimiters(ConfigParserTestCase):
+    delimiters = (':=', '$')
+    comment_prefixes = ('//', '"')
+
+class MultilineValuesTestCase(BasicTestCase):
     config_class = configparser.ConfigParser
     wonderful_spam = ("I'm having spam spam spam spam "
                       "spam spam spam beaked beans spam "
@@ -442,7 +486,7 @@ class MultilineValuesTestCase(TestCaseBase):
         self.assertEqual(cf_from_file.get('section8', 'lovely_spam4'),
                          self.wonderful_spam.replace('\t\n', '\n'))
 
-class RawConfigParserTestCase(TestCaseBase):
+class RawConfigParserTestCase(BasicTestCase):
     config_class = configparser.RawConfigParser
 
     def test_interpolation(self):
@@ -476,6 +520,28 @@ class RawConfigParserTestCase(TestCaseBase):
                          [0, 1, 1, 2, 3, 5, 8, 13])
         self.assertEqual(cf.get('non-string', 'dict'), {'pi': 3.14159})
 
+class RawConfigParserTestCaseNonStandardDelimiters(RawConfigParserTestCase):
+    delimiters = (':=', '$')
+    comment_prefixes = ('//', '"')
+
+class RawConfigParserTestSambaConf(BasicTestCase):
+    config_class = configparser.RawConfigParser
+    comment_prefixes = ('#', ';', '//', '----')
+    empty_lines_in_values = False
+
+    def test_reading(self):
+        smbconf = support.findfile("cfgparser.2")
+        # check when we pass a mix of readable and non-readable files:
+        cf = self.newconfig()
+        parsed_files = cf.read([smbconf, "nonexistent-file"])
+        self.assertEqual(parsed_files, [smbconf])
+        sections = ['global', 'homes', 'printers',
+                    'print$', 'pdf-generator', 'tmp', 'Agustin']
+        self.assertEqual(cf.sections(), sections)
+        self.assertEqual(cf.get("global", "workgroup"), "MDKGROUP")
+        self.assertEqual(cf.getint("global", "max log size"), 50)
+        self.assertEqual(cf.get("global", "hosts allow"), "127.")
+        self.assertEqual(cf.get("tmp", "echo command"), "cat %s; rm %s")
 
 class SafeConfigParserTestCase(ConfigParserTestCase):
     config_class = configparser.SafeConfigParser
@@ -483,16 +549,17 @@ class SafeConfigParserTestCase(ConfigParserTestCase):
     def test_safe_interpolation(self):
         # See http://www.python.org/sf/511737
         cf = self.fromstring("[section]\n"
-                             "option1=xxx\n"
-                             "option2=%(option1)s/xxx\n"
-                             "ok=%(option1)s/%%s\n"
-                             "not_ok=%(option2)s/%%s")
+                             "option1{eq}xxx\n"
+                             "option2{eq}%(option1)s/xxx\n"
+                             "ok{eq}%(option1)s/%%s\n"
+                             "not_ok{eq}%(option2)s/%%s".format(
+                                 eq=self.delimiters[0]))
         self.assertEqual(cf.get("section", "ok"), "xxx/%s")
         self.assertEqual(cf.get("section", "not_ok"), "xxx/xxx/%s")
 
     def test_set_malformatted_interpolation(self):
         cf = self.fromstring("[sect]\n"
-                             "option1=foo\n")
+                             "option1{eq}foo\n".format(eq=self.delimiters[0]))
 
         self.assertEqual(cf.get('sect', "option1"), "foo")
 
@@ -508,7 +575,7 @@ class SafeConfigParserTestCase(ConfigParserTestCase):
 
     def test_set_nonstring_types(self):
         cf = self.fromstring("[sect]\n"
-                             "option1=foo\n")
+                             "option1{eq}foo\n".format(eq=self.delimiters[0]))
         # Check that we get a TypeError when setting non-string values
         # in an existing section:
         self.assertRaises(TypeError, cf.set, "sect", "option1", 1)
@@ -526,15 +593,16 @@ class SafeConfigParserTestCase(ConfigParserTestCase):
         cf = self.newconfig()
         self.assertRaises(ValueError, cf.add_section, "DEFAULT")
 
+class SafeConfigParserTestCaseNonStandardDelimiters(SafeConfigParserTestCase):
+    delimiters = (':=', '$')
+    comment_prefixes = ('//', '"')
 
 class SafeConfigParserTestCaseNoValue(SafeConfigParserTestCase):
     allow_no_value = True
 
 
 class SortedTestCase(RawConfigParserTestCase):
-    def newconfig(self, defaults=None):
-        self.cf = self.config_class(defaults=defaults, dict_type=SortedDict)
-        return self.cf
+    dict_type = SortedDict
 
     def test_sorted(self):
         self.fromstring("[b]\n"
@@ -556,14 +624,36 @@ class SortedTestCase(RawConfigParserTestCase):
                           "o4 = 1\n\n")
 
 
+class CompatibleTestCase(CfgParserTestCaseClass):
+    config_class = configparser.RawConfigParser
+    comment_prefixes = configparser.RawConfigParser._COMPATIBLE
+
+    def test_comment_handling(self):
+        config_string = textwrap.dedent("""\
+        [Commented Bar]
+        baz=qwe ; a comment
+        foo: bar # not a comment!
+        # but this is a comment
+        ; another comment
+        """)
+        cf = self.fromstring(config_string)
+        self.assertEqual(cf.get('Commented Bar', 'foo'), 'bar # not a comment!')
+        self.assertEqual(cf.get('Commented Bar', 'baz'), 'qwe')
+
+
 def test_main():
     support.run_unittest(
         ConfigParserTestCase,
+        ConfigParserTestCaseNonStandardDelimiters,
         MultilineValuesTestCase,
         RawConfigParserTestCase,
+        RawConfigParserTestCaseNonStandardDelimiters,
+        RawConfigParserTestSambaConf,
         SafeConfigParserTestCase,
+        SafeConfigParserTestCaseNonStandardDelimiters,
         SafeConfigParserTestCaseNoValue,
         SortedTestCase,
+        CompatibleTestCase,
         )
 
 

Misc/NEWS

@@ -475,6 +475,9 @@ C-API
 Library
 -------
 
+- Issue #1682942: Improvements to configparser: support alternate
+  delimiters, alternate comment prefixes and empty lines in values.
+
 - Issue #9354: Provide getsockopt() in asyncore's file_wrapper.
 
 - Issue #8966: ctypes: Remove implicit bytes-unicode conversion.