python · arturoescaip · May 15, 2020 · May 24, 2020 · May 15, 2020 · May 15, 2020
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -7,11 +7,13 @@ on:
   push:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
   pull_request:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
 
@@ -38,7 +40,7 @@ jobs:
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Build CPython
       run: .\PCbuild\build.bat -e -p Win32
     - name: Display build info
@@ -52,7 +54,7 @@ jobs:
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Build CPython
       run: .\PCbuild\build.bat -e -p x64
     - name: Display build info
@@ -66,7 +68,7 @@ jobs:
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Configure CPython
       run: ./configure --with-pydebug --with-openssl=/usr/local/opt/openssl --prefix=/opt/python-dev
     - name: Build CPython
@@ -84,7 +86,7 @@ jobs:
     env:
       OPENSSL_VER: 1.1.1f
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install Dependencies
       run: sudo ./.github/workflows/posix-deps-apt.sh
     - name: 'Restore OpenSSL build'

diff --git a/.github/workflows/build_msi.yml b/.github/workflows/build_msi.yml
@@ -4,13 +4,15 @@ on:
   push:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
     paths:
     - 'Tools/msi/**'
   pull_request:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
     paths:
@@ -21,14 +23,14 @@ jobs:
     name: 'Windows (x86) Installer'
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Build CPython installer
       run: .\Tools\msi\build.bat -x86
 
   build_win_amd64:
     name: 'Windows (x64) Installer'
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Build CPython installer
       run: .\Tools\msi\build.bat -x64
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
@@ -4,6 +4,7 @@ on:
   push:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
     paths-ignore:
@@ -12,6 +13,7 @@ on:
   #pull_request:
   #  branches:
   #  - master
+  #  - 3.9
   #  - 3.8
   #  - 3.7
   #  paths-ignore:
@@ -25,7 +27,7 @@ jobs:
     env:
       OPENSSL_VER: 1.1.1f
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install Dependencies
       run: sudo ./.github/workflows/posix-deps-apt.sh
     - name: 'Restore OpenSSL build'
@@ -48,6 +50,7 @@ jobs:
         ./python -m venv .venv
         source ./.venv/bin/activate
         python -m pip install -U coverage
+        python -m pip install -r Misc/requirements-test.txt
         python -m test.pythoninfo
     - name: 'Tests with coverage'
       run: >
@@ -73,7 +76,7 @@ jobs:
     name: 'Ubuntu (C Coverage)'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install Dependencies
       run: sudo ./.github/workflows/posix-deps-apt.sh
     - name: Configure CPython

diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
@@ -4,13 +4,15 @@ on:
   #push:
   #  branches:
   #  - master
+  #  - 3.9
   #  - 3.8
   #  - 3.7
   #  paths:
   #  - 'Doc/**'
   pull_request:
     branches:
     - master
+    - 3.9
     - 3.8
     - 3.7
     paths:
@@ -22,7 +24,7 @@ jobs:
     name: 'Docs'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: 'Install Dependencies'
       run: sudo ./.github/workflows/posix-deps-apt.sh && sudo apt-get install wamerican
     - name: 'Configure CPython'

diff --git a/.travis.yml b/.travis.yml
@@ -87,6 +87,7 @@ matrix:
         # Need a venv that can parse covered code.
         - ./python -m venv venv
         - ./venv/bin/python -m pip install -U coverage
+        - ./venv/bin/python -m pip install -r Misc/requirements-test.txt
         - ./venv/bin/python -m test.pythoninfo
       script:
         # Skip tests that re-run the entire test suite.

diff --git a/Doc/howto/argparse.rst b/Doc/howto/argparse.rst
@@ -353,7 +353,7 @@ Our program keeps growing in complexity::
    args = parser.parse_args()
    answer = args.square**2
    if args.verbose:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    else:
        print(answer)
 
@@ -387,9 +387,9 @@ multiple verbosity values, and actually get to use them::
    args = parser.parse_args()
    answer = args.square**2
    if args.verbosity == 2:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    elif args.verbosity == 1:
-       print("{}^2 == {}".format(args.square, answer))
+       print(f"{args.square}^2 == {answer}")
    else:
        print(answer)
 
@@ -421,9 +421,9 @@ Let's fix it by restricting the values the ``--verbosity`` option can accept::
    args = parser.parse_args()
    answer = args.square**2
    if args.verbosity == 2:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    elif args.verbosity == 1:
-       print("{}^2 == {}".format(args.square, answer))
+       print(f"{args.square}^2 == {answer}")
    else:
        print(answer)
 
@@ -461,9 +461,9 @@ verbosity argument (check the output of ``python --help``)::
    args = parser.parse_args()
    answer = args.square**2
    if args.verbosity == 2:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    elif args.verbosity == 1:
-       print("{}^2 == {}".format(args.square, answer))
+       print(f"{args.square}^2 == {answer}")
    else:
        print(answer)
 
@@ -529,9 +529,9 @@ Let's fix::
 
    # bugfix: replace == with >=
    if args.verbosity >= 2:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    elif args.verbosity >= 1:
-       print("{}^2 == {}".format(args.square, answer))
+       print(f"{args.square}^2 == {answer}")
    else:
        print(answer)
 
@@ -566,9 +566,9 @@ Let's fix that bug::
    args = parser.parse_args()
    answer = args.square**2
    if args.verbosity >= 2:
-       print("the square of {} equals {}".format(args.square, answer))
+       print(f"the square of {args.square} equals {answer}")
    elif args.verbosity >= 1:
-       print("{}^2 == {}".format(args.square, answer))
+       print(f"{args.square}^2 == {answer}")
    else:
        print(answer)
 
@@ -606,9 +606,9 @@ not just squares::
    args = parser.parse_args()
    answer = args.x**args.y
    if args.verbosity >= 2:
-       print("{} to the power {} equals {}".format(args.x, args.y, answer))
+       print(f"{args.x} to the power {args.y} equals {answer}")
    elif args.verbosity >= 1:
-       print("{}^{} == {}".format(args.x, args.y, answer))
+       print(f"{args.x}^{args.y} == {answer}")
    else:
        print(answer)
 
@@ -645,9 +645,9 @@ to display *more* text instead::
    args = parser.parse_args()
    answer = args.x**args.y
    if args.verbosity >= 2:
-       print("Running '{}'".format(__file__))
+       print(f"Running '{__file__}'")
    if args.verbosity >= 1:
-       print("{}^{} == ".format(args.x, args.y), end="")
+       print(f"{args.x}^{args.y} == ", end="")
    print(answer)
 
 Output:
@@ -688,9 +688,9 @@ which will be the opposite of the ``--verbose`` one::
    if args.quiet:
        print(answer)
    elif args.verbose:
-       print("{} to the power {} equals {}".format(args.x, args.y, answer))
+       print(f"{args.x} to the power {args.y} equals {answer}")
    else:
-       print("{}^{} == {}".format(args.x, args.y, answer))
+       print(f"{args.x}^{args.y} == {answer}")
 
 Our program is now simpler, and we've lost some functionality for the sake of
 demonstration. Anyways, here's the output:

diff --git a/Doc/howto/sockets.rst b/Doc/howto/sockets.rst
@@ -319,7 +319,7 @@ inside-out.
 
 In Python, you use ``socket.setblocking(False)`` to make it non-blocking. In C, it's
 more complex, (for one thing, you'll need to choose between the BSD flavor
-``O_NONBLOCK`` and the almost indistinguishable Posix flavor ``O_NDELAY``, which
+``O_NONBLOCK`` and the almost indistinguishable POSIX flavor ``O_NDELAY``, which
 is completely different from ``TCP_NODELAY``), but it's the exact same idea. You
 do this after creating the socket, but before using it. (Actually, if you're
 nuts, you can switch back and forth.)

diff --git a/Doc/library/asyncio-api-index.rst b/Doc/library/asyncio-api-index.rst
@@ -48,6 +48,9 @@ await on multiple things with timeouts.
     * - :class:`Task`
       - Task object.
 
+    * - :func:`to_thread`
+      - Asychronously run a function in a separate OS thread.
+
     * - :func:`run_coroutine_threadsafe`
       - Schedule a coroutine from another OS thread.
 

diff --git a/Doc/library/asyncio-future.rst b/Doc/library/asyncio-future.rst
@@ -170,14 +170,17 @@ Future Object
       Returns the number of callbacks removed, which is typically 1,
       unless a callback was added more than once.
 
-   .. method:: cancel()
+   .. method:: cancel(msg=None)
 
       Cancel the Future and schedule callbacks.
 
       If the Future is already *done* or *cancelled*, return ``False``.
       Otherwise, change the Future's state to *cancelled*,
       schedule the callbacks, and return ``True``.
 
+      .. versionchanged:: 3.9
+         Added the ``msg`` parameter.
+
    .. method:: exception()
 
       Return the exception that was set on this Future.
@@ -255,3 +258,6 @@ the Future has a result::
    - asyncio Future is not compatible with the
      :func:`concurrent.futures.wait` and
      :func:`concurrent.futures.as_completed` functions.
+
+   - :meth:`asyncio.Future.cancel` accepts an optional ``msg`` argument,
+     but :func:`concurrent.futures.cancel` does not.