Closes #18430: Document that peek() may change the position of the underlying

file for the BZ2File, GzipFile and LZMAFile classes.

diff --cc Doc/library/bz2.rst
Simple merge

diff --cc Doc/library/gzip.rst
Simple merge

diff --cc Doc/library/lzma.rst
index 53fba89f1a66fd7636835cff260afad979afe062,07b69eb772a1c7fbfe5cee14fe452b0453c92a00..b71051da85c12145b01bb2d6162f76766592ece5
--- 1/Doc/library/lzma.rst
--- 2/Doc/library/lzma.rst
+++ b/Doc/library/lzma.rst
@@@ -102,9 -98,11 +102,14 @@@ Reading and writing compressed file
        byte of data will be returned, unless EOF has been reached. The exact
        number of bytes returned is unspecified (the *size* argument is ignored).
  
+       .. note:: While calling :meth:`peek` does not change the file position of
+          the :class:`LZMAFile`, it may change the position of the underlying
+          file object (e.g. if the :class:`LZMAFile` was constructed by passing a
+          file object for *filename*).
+ 
 +   .. versionchanged:: 3.4
 +      Added support for the ``"x"`` and ``"xb"`` modes.
 +
  
  Compressing and decompressing data in memory
  --------------------------------------------