bpo-37330: open() no longer accept 'U' in file mode (GH-16959)
open(), io.open(), codecs.open() and fileinput.FileInput no longer
accept "U" ("universal newline") in the file mode. This flag was
deprecated since Python 3.3.diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index c1bdac7..e819b0a 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -71,7 +71,6 @@
'b' binary mode
't' text mode (default)
'+' open a disk file for updating (reading and writing)
- 'U' universal newline mode (deprecated)
========= ===============================================================
The default mode is 'rt' (open for reading text). For binary random
@@ -87,10 +86,6 @@
returned as strings, the bytes having been first decoded using a
platform-dependent encoding or using the specified encoding if given.
- 'U' mode is deprecated and will raise an exception in future versions
- of Python. It has no effect in Python 3. Use newline to control
- universal newlines mode.
-
buffering is an optional integer used to set the buffering policy.
Pass 0 to switch buffering off (only allowed in binary mode), 1 to select
line buffering (only usable in text mode), and an integer > 1 to indicate
@@ -176,7 +171,7 @@
if errors is not None and not isinstance(errors, str):
raise TypeError("invalid errors: %r" % errors)
modes = set(mode)
- if modes - set("axrwb+tU") or len(mode) > len(modes):
+ if modes - set("axrwb+t") or len(mode) > len(modes):
raise ValueError("invalid mode: %r" % mode)
creating = "x" in modes
reading = "r" in modes
@@ -185,13 +180,6 @@
updating = "+" in modes
text = "t" in modes
binary = "b" in modes
- if "U" in modes:
- if creating or writing or appending or updating:
- raise ValueError("mode U cannot be combined with 'x', 'w', 'a', or '+'")
- import warnings
- warnings.warn("'U' mode is deprecated",
- DeprecationWarning, 2)
- reading = True
if text and binary:
raise ValueError("can't have text and binary mode at once")
if creating + reading + writing + appending > 1: