bpo-27351: Fix ConfigParser.read() documentation and docstring (GH-8123)

Switch "list" with "iterable" to match with the implementation.

Doc/library/configparser.rst

@@ -963,16 +963,17 @@ ConfigParser Objects
 
    .. method:: read(filenames, encoding=None)
 
-      Attempt to read and parse a list of filenames, returning a list of
+      Attempt to read and parse an iterable of filenames, returning a list of
       filenames which were successfully parsed.
 
       If *filenames* is a string, a :class:`bytes` object or a
       :term:`path-like object`, it is treated as
       a single filename.  If a file named in *filenames* cannot be opened, that
-      file will be ignored.  This is designed so that you can specify a list of
-      potential configuration file locations (for example, the current
-      directory, the user's home directory, and some system-wide directory),
-      and all existing configuration files in the list will be read.
+      file will be ignored.  This is designed so that you can specify an
+      iterable of potential configuration file locations (for example, the
+      current directory, the user's home directory, and some system-wide
+      directory), and all existing configuration files in the iterable will be
+      read.
 
       If none of the named files exist, the :class:`ConfigParser`
       instance will contain an empty dataset.  An application which requires

Lib/configparser.py

@@ -80,7 +80,7 @@ ConfigParser -- responsible for parsing a list of
         Return list of configuration options for the named section.
 
     read(filenames, encoding=None)
-        Read and parse the list of named configuration files, given by
+        Read and parse the iterable of named configuration files, given by
         name.  A single filename is also allowed.  Non-existing files
         are ignored.  Return list of successfully read files.
 
@@ -677,13 +677,13 @@ class RawConfigParser(MutableMapping):
         return list(opts.keys())
 
     def read(self, filenames, encoding=None):
-        """Read and parse a filename or a list of filenames.
+        """Read and parse a filename or an iterable of filenames.
 
         Files that cannot be opened are silently ignored; this is
-        designed so that you can specify a list of potential
+        designed so that you can specify an iterable of potential
         configuration file locations (e.g. current directory, user's
         home directory, systemwide directory), and all existing
-        configuration files in the list will be read.  A single
+        configuration files in the iterable will be read.  A single
         filename may also be given.
 
         Return list of successfully read files.