venv: Add a command-line package for creating virtual environments.

Works like "python -m venv path" and creates a rudimentary virtual environment for the Unix port: - sets MICROPYPATH - copies the micropython binary to venv/bin/micropython which is in $PATH - installs mip & mip-cmdline in the venv Using the venv is the same as for CPython -- source the activate script to enter, and call the deactivate function to leave. This work was funded through GitHub Sponsors. Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

Author: jimmo

python-stdlib/venv/manifest.py

@@ -0,0 +1,9 @@
+metadata(
+ version="0.1.0",
+ description="Support for creating MicroPython virtual environments using `micropython -m venv`",
+)
+
+require("argparse")
+require("mip-cmdline")
+
+package("venv")

python-stdlib/venv/venv/__main__.py

@@ -0,0 +1,99 @@
+# Support for creating MicroPython virtual environments using `micropython -m venv`
+# MIT license; Copyright (c) 2022 Jim Mussared
+
+import argparse
+import os
+import sys
+
+
+# If mip is not frozen into this binary, then also install it in the venv.
+def install_mip(venv_lib_path):
+ need_mip = False
+ if "mip" in sys.modules:
+ del sys.modules["mip"]
+ saved_sys_path = sys.path[:]
+ try:
+ sys.path[:] = [".frozen"]
+ try:
+ import mip
+
+ print("mip is frozen")
+ except ImportError:
+ need_mip = True
+ finally:
+ sys.path[:] = saved_sys_path
+
+ if need_mip:
+ import mip
+
+ mip.install("mip-cmdline", target=venv_lib_path)
+
+
+def do_venv():
+ parser = argparse.ArgumentParser(description="Create a micropython virtual environment")
+ parser.add_argument("path", nargs=1, help="Path to create the virtual environment in")
+ args = parser.parse_args(args=sys.argv[1:])
+ venv_path = args.path[0]
+ print("Creating virtual environment in:", venv_path)
+
+ # Equivalent to path = os.abspath(path).
+ if not venv_path.startswith("/"):
+ venv_path = os.getcwd() + os.sep + venv_path
+
+ venv_bin_path = venv_path + os.sep + "bin"
+ venv_lib_path = venv_path + os.sep + "lib"
+
+ for d in (
+ venv_path,
+ venv_bin_path,
+ venv_lib_path,
+ ):
+ try:
+ os.mkdir(d)
+ except:
+ pass
+
+ # Note the venv/lib dir goes before .frozen so that installed packages replace frozen ones.
+ with open(venv_bin_path + os.sep + "activate", "w") as f:
+ print(
+ """# Usage: source bin/activate
+
+deactivate() {{
+ PATH="$_OLD_VIRTUAL_PATH"
+ export PATH
+
+ MICROPYPATH="$_OLD_VIRTUAL_MICROPYPATH"
+ if [ -z "$MICROPYPATH" ]; then
+ export -n MICROPYPATH
+ else
+ export MICROPYPATH
+ fi
+
+ unset VIRTUAL_ENV
+
+ unset deactivate
+}}
+
+VIRTUAL_ENV={}
+
+_OLD_VIRTUAL_PATH="$PATH"
+PATH="$VIRTUAL_ENV/bin:$PATH"
+export PATH
+
+_OLD_VIRTUAL_MICROPYPATH="$MICROPYPATH"
+MICROPYPATH="$VIRTUAL_ENV/lib:.frozen"
+export MICROPYPATH
+""".format(
+ venv_path
+ ),
+ file=f,
+ )
+
+ # Add a `micropython` binary in $PATH pointing to this binary.
+ if hasattr(sys, "executable"):
+ os.system("cp {} {}".format(sys.executable, venv_bin_path + os.sep + "micropython"))
+
+ install_mip(venv_lib_path)
+
+
+do_venv()