general: Remove Python 2.7 support.

Python 2.7 has been EOL since January 2020.

Ubuntu oldoldlts (Focal Fossa, 20.04) has Python 3.8.
Debian oldoldstable (Buster, from 2019) has Python 3.7.
RHEL 8 (from 2019) has Python 3.6.

It's easier than ever to install a modern Python using uv.

Given this, it seems like a fine idea to drop Python 2.7 support.

Even though the build is not tested on Python as old as 3.3, I
left comments stating that "3.3+" is the baseline Python version.
However, it might make sense to bump this to e.g., 3.10, the oldest
Python 3 version used during CI. Or, using uv or another method
actually test on the oldest Python interpreter that is desirable
to support (uv goes back to Python 3.7 easily; in October 2025, the
oldest supported Python interpreter version will be 3.10)

Signed-off-by: Jeff Epler <jepler@gmail.com>

.github/workflows/mpy_format.yml

@@ -15,7 +15,7 @@ concurrency:
 
 jobs:
   test:
-    runs-on: ubuntu-22.04 # use 22.04 to get python2
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
     - name: Install packages

.github/workflows/ports_unix.yml

@@ -121,7 +121,7 @@ jobs:
       run: tests/run-tests.py --print-failures
 
   nanbox:
-    runs-on: ubuntu-22.04 # use 22.04 to get python2, and libffi-dev:i386
+    runs-on: ubuntu-22.04 # use 22.04 to get libffi-dev:i386
     steps:
     - uses: actions/checkout@v4
     - name: Install packages
@@ -135,7 +135,7 @@ jobs:
       run: tests/run-tests.py --print-failures
 
   longlong:
-    runs-on: ubuntu-22.04 # use 22.04 to get python2, and libffi-dev:i386
+    runs-on: ubuntu-22.04 # use 22.04 to get libffi-dev:i386
     steps:
     - uses: actions/checkout@v4
     - name: Install packages

README.md

@@ -80,9 +80,8 @@ This repository contains the following components:
 - [examples/](examples/) -- a few example Python scripts.
 
 "make" is used to build the components, or "gmake" on BSD-based systems.
-You will also need bash, gcc, and Python 3.3+ available as the command `python3`
-(if your system only has Python 2.7 then invoke make with the additional option
-`PYTHON=python2`). Some ports (rp2 and esp32) additionally use CMake.
+You will also need bash, gcc, and Python 3.3+ available as the command `python3`.
+Some ports (rp2 and esp32) additionally use CMake.
 
 Supported platforms & architectures
 -----------------------------------

docs/develop/gettingstarted.rst

@@ -106,7 +106,7 @@ See the `ARM GCC
 toolchain <https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads>`_
 for the latest details.
 
-Python is also required. Python 2 is supported for now, but we recommend using Python 3.
+Python 3 is also required.
 Check that you have Python available on your system:
 
 .. code-block:: bash

ports/stm32/boards/pllvalues.py

@@ -105,7 +105,7 @@ def compute_pll2(hse, sys, relax_pll48):
         # VCO_OUT must be between 192MHz and 432MHz
         if sys * P not in mcu.range_vco_out:
             continue
-        NbyM = float(sys * P) / hse  # float for Python 2
+        NbyM = sys * P / hse
         # scan M
         M_min = mcu.range_n[0] // int(round(NbyM))  # starting value
         while mcu.range_vco_in[-1] * M_min < hse:
@@ -121,7 +121,7 @@ def compute_pll2(hse, sys, relax_pll48):
             # N is restricted
             if N not in mcu.range_n:
                 continue
-            Q = float(sys * P) / 48  # float for Python 2
+            Q = sys * P / 48
             # Q must be an integer in a set range
             if close_int(Q) and round(Q) in mcu.range_q:
                 # found valid values
@@ -142,7 +142,6 @@ def compute_pll2(hse, sys, relax_pll48):
 
 
 def compute_derived(hse, pll):
-    hse = float(hse)  # float for Python 2
     M, N, P, Q = pll
     vco_in = hse / M
     vco_out = hse * N / M

ports/stm32/make-stmconst.py

@@ -9,25 +9,13 @@ from __future__ import print_function
 import argparse
 import re
 
-# Python 2/3 compatibility
-import platform
 
-if platform.python_version_tuple()[0] == "2":
-
-    def convert_bytes_to_str(b):
-        return b
-
-elif platform.python_version_tuple()[0] == "3":
-
-    def convert_bytes_to_str(b):
-        try:
-            return str(b, "utf8")
-        except ValueError:
-            # some files have invalid utf8 bytes, so filter them out
-            return "".join(chr(l) for l in b if l <= 126)
-
-
-# end compatibility code
+def convert_bytes_to_str(b):
+    try:
+        return str(b, "utf8")
+    except ValueError:
+        # some files have invalid utf8 bytes, so filter them out
+        return "".join(chr(l) for l in b if l <= 126)
 
 
 # given a list of (name,regex) pairs, find the first one that matches the given line

py/makeqstrdata.py

@@ -1,7 +1,7 @@
 """
 Process raw qstr file and output qstr data with length, hash and data bytes.
 
-This script works with Python 2.6, 2.7, 3.3 and 3.4.
+This script works with Python 3.3+.
 """
 
 from __future__ import print_function
@@ -9,13 +9,7 @@ from __future__ import print_function
 import re
 import sys
 
-# Python 2/3/MicroPython compatibility:
-#   - iterating through bytes is different
-#   - codepoint2name from html.entities is hard-coded
-if sys.version_info[0] == 2:
-    bytes_cons = lambda val, enc=None: bytearray(val)
-elif sys.version_info[0] == 3:  # Also handles MicroPython
-    bytes_cons = bytes
+bytes_cons = bytes
 
 # fmt: off
 codepoint2name = {
@@ -57,7 +51,6 @@ codepoint2name = {
     253: "yacute", 165: "yen", 255: "yuml", 950: "zeta", 8205: "zwj", 8204: "zwnj"
 }
 # fmt: on
-# end compatibility code
 
 codepoint2name[ord("-")] = "hyphen"
 

py/makeqstrdefs.py

@@ -2,7 +2,7 @@
 This script processes the output from the C preprocessor and extracts all
 qstr. Each qstr is transformed into a qstr definition of the form 'Q(...)'.
 
-This script works with Python 2.6, 2.7, 3.3 and 3.4.
+This script works with Python 3.3+.
 """
 
 from __future__ import print_function

py/makeversionhdr.py

@@ -1,7 +1,7 @@
 """
 Generate header file with macros defining MicroPython version info.
 
-This script works with Python 2.6, 2.7, 3.3 and 3.4.
+This script works with Python 3.3+.
 """
 
 from __future__ import print_function
@@ -22,12 +22,6 @@ import subprocess
 #   "vX.Y.Z-preview.N.gHASH.dirty" -- building at any subsequent commit in the cycle
 #                                     with local changes
 def get_version_info_from_git(repo_path):
-    # Python 2.6 doesn't have check_output, so check for that
-    try:
-        subprocess.check_output
-    except AttributeError:
-        return None
-
     # Note: git describe doesn't work if no tag is available
     try:
         git_tag = subprocess.check_output(
@@ -48,12 +42,6 @@ def get_version_info_from_git(repo_path):
 
 
 def get_hash_from_git(repo_path):
-    # Python 2.6 doesn't have check_output, so check for that.
-    try:
-        subprocess.check_output
-    except AttributeError:
-        return None
-
     try:
         return subprocess.check_output(
             ["git", "rev-parse", "--short", "HEAD"],

tools/ci.sh

@@ -127,15 +127,12 @@ function ci_code_size_build {
 
 function ci_mpy_format_setup {
     sudo apt-get update
-    sudo apt-get install python2.7
     sudo pip3 install pyelftools
-    python2.7 --version
     python3 --version
 }
 
 function ci_mpy_format_test {
     # Test mpy-tool.py dump feature on bytecode
-    python2.7 ./tools/mpy-tool.py -xd tests/frozen/frozentest.mpy
     python3 ./tools/mpy-tool.py -xd tests/frozen/frozentest.mpy
 
     # Build MicroPython
@@ -666,12 +663,11 @@ function ci_unix_coverage_run_native_mpy_tests {
 function ci_unix_32bit_setup {
     sudo dpkg --add-architecture i386
     sudo apt-get update
-    sudo apt-get install gcc-multilib g++-multilib libffi-dev:i386 python2.7
+    sudo apt-get install gcc-multilib g++-multilib libffi-dev:i386
     sudo pip3 install setuptools
     sudo pip3 install pyelftools
     sudo pip3 install ar
     gcc --version
-    python2.7 --version
     python3 --version
 }
 
@@ -689,13 +685,12 @@ function ci_unix_coverage_32bit_run_native_mpy_tests {
 }
 
 function ci_unix_nanbox_build {
-    # Use Python 2 to check that it can run the build scripts
-    ci_unix_build_helper PYTHON=python2.7 VARIANT=nanbox CFLAGS_EXTRA="-DMICROPY_PY_MATH_CONSTANTS=1"
+    ci_unix_build_helper VARIANT=nanbox CFLAGS_EXTRA="-DMICROPY_PY_MATH_CONSTANTS=1"
     ci_unix_build_ffi_lib_helper gcc -m32
 }
 
 function ci_unix_nanbox_run_tests {
-    ci_unix_run_tests_full_no_native_helper nanbox PYTHON=python2.7
+    ci_unix_run_tests_full_no_native_helper nanbox
 }
 
 function ci_unix_longlong_build {

tools/mpy-tool.py

@@ -24,40 +24,20 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-# Python 2/3/MicroPython compatibility code
-from __future__ import print_function
-import sys
-
-if sys.version_info[0] == 2:
-    from binascii import hexlify as hexlify_py2
-
-    str_cons = lambda val, enc=None: str(val)
-    bytes_cons = lambda val, enc=None: bytearray(val)
-    is_str_type = lambda o: isinstance(o, str)
-    is_bytes_type = lambda o: type(o) is bytearray
-    is_int_type = lambda o: isinstance(o, int) or isinstance(o, long)  # noqa: F821
-
-    def hexlify_to_str(b):
-        x = hexlify_py2(b)
-        return ":".join(x[i : i + 2] for i in range(0, len(x), 2))
-
-elif sys.version_info[0] == 3:  # Also handles MicroPython
-    from binascii import hexlify
-
-    str_cons = str
-    bytes_cons = bytes
-    is_str_type = lambda o: isinstance(o, str)
-    is_bytes_type = lambda o: isinstance(o, bytes)
-    is_int_type = lambda o: isinstance(o, int)
-
-    def hexlify_to_str(b):
-        return str(hexlify(b, ":"), "ascii")
-
-
-# end compatibility code
-
-import sys
 import struct
+import sys
+from binascii import hexlify
+
+str_cons = str
+bytes_cons = bytes
+is_str_type = lambda o: isinstance(o, str)
+is_bytes_type = lambda o: isinstance(o, bytes)
+is_int_type = lambda o: isinstance(o, int)
+
+
+def hexlify_to_str(b):
+    return str(hexlify(b, ":"), "ascii")
+
 
 sys.path.append(sys.path[0] + "/../py")
 import makeqstrdata as qstrutil

tools/pydfu.py

@@ -77,7 +77,7 @@ __DFU_INTERFACE = 0
 
 # Python 3 deprecated getargspec in favour of getfullargspec, but
 # Python 2 doesn't have the latter, so detect which one to use
-getargspec = getattr(inspect, "getfullargspec", getattr(inspect, "getargspec", None))
+getargspec = inspect.getfullargspec
 
 if "length" in getargspec(usb.util.get_string).args:
     # PyUSB 1.0.0.b1 has the length argument