bpo-29770: remove outdated PYO related info (GH-590)

Modules/main.c

@@ -53,7 +53,7 @@ static const char usage_1[] = "\
 Options and arguments (and corresponding environment variables):\n\
 -b     : issue warnings about str(bytes_instance), str(bytearray_instance)\n\
          and comparing bytes/bytearray with str. (-bb: issue errors)\n\
--B     : don't write .py[co] files on import; also PYTHONDONTWRITEBYTECODE=x\n\
+-B     : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x\n\
 -c cmd : program passed in as string (terminates option list)\n\
 -d     : debug output from parser; also PYTHONDEBUG=x\n\
 -E     : ignore PYTHON* environment variables (such as PYTHONPATH)\n\

Modules/zipimport.c

@@ -1101,7 +1101,7 @@ get_decompress_func(void)
     _Py_IDENTIFIER(decompress);
 
     if (importing_zlib != 0)
-        /* Someone has a zlib.py[co] in their Zip file;
+        /* Someone has a zlib.pyc in their Zip file;
            let's avoid a stack overflow. */
         return NULL;
     importing_zlib = 1;
@@ -1260,7 +1260,7 @@ eq_mtime(time_t t1, time_t t2)
     return d <= 1;
 }
 
-/* Given the contents of a .py[co] file in a buffer, unmarshal the data
+/* Given the contents of a .pyc file in a buffer, unmarshal the data
    and return the code object. Return None if it the magic word doesn't
    match (we do this instead of raising an exception as we fall back
    to .py if available and we don't want to mask other errors).
@@ -1400,7 +1400,7 @@ get_mtime_of_source(ZipImporter *self, PyObject *path)
     PyObject *toc_entry, *stripped;
     time_t mtime;
 
-    /* strip 'c' or 'o' from *.py[co] */
+    /* strip 'c' from *.pyc */
     if (PyUnicode_READY(path) == -1)
         return (time_t)-1;
     stripped = PyUnicode_FromKindAndData(PyUnicode_KIND(path),