Activation scripts for next-gen virtualenv (#1454)

2 files changed, 64 insertions, 0 deletions

diff --git a/src/virtualenv/activation/python/__init__.py b/src/virtualenv/activation/python/__init__.py
new file mode 100644
index 0000000..1d73e99
--- /dev/null
+++ b/src/virtualenv/activation/python/__init__.py
@@ -0,0 +1,19 @@
+from __future__ import absolute_import, unicode_literals
+
+import json
+import os
+
+from pathlib2 import Path
+
+from ..via_template import ViaTemplateActivator
+
+
+class PythonActivator(ViaTemplateActivator):
+    def templates(self):
+        yield Path("activate_this.py")
+
+    def replacements(self, creator, dest_folder):
+        replacements = super(PythonActivator, self).replacements(creator, dest_folder)
+        site_dump = json.dumps([os.path.relpath(str(i), str(dest_folder)) for i in creator.site_packages], indent=2)
+        replacements.update({"__SITE_PACKAGES__": site_dump})
+        return replacements
diff --git a/src/virtualenv/activation/python/activate_this.py b/src/virtualenv/activation/python/activate_this.py
new file mode 100644
index 0000000..fc8d449
--- /dev/null
+++ b/src/virtualenv/activation/python/activate_this.py
@@ -0,0 +1,45 @@
+"""Activate virtualenv for current interpreter:
+
+Use exec(open(this_file).read(), {'__file__': this_file}).
+
+This can be used when you must use an existing Python interpreter, not the virtualenv bin/python.
+"""
+import json
+import os
+import site
+import sys
+
+try:
+    __file__
+except NameError:
+    raise AssertionError("You must use exec(open(this_file).read(), {'__file__': this_file}))")
+
+# prepend bin to PATH (this file is inside the bin directory)
+bin_dir = os.path.dirname(os.path.abspath(__file__))
+os.environ["PATH"] = os.pathsep.join([bin_dir] + os.environ.get("PATH", "").split(os.pathsep))
+
+base = os.path.dirname(bin_dir)
+
+# virtual env is right above bin directory
+os.environ["VIRTUAL_ENV"] = base
+
+# add the virtual environments site-packages to the host python import mechanism
+prev = set(sys.path)
+
+# fmt: off
+# turn formatter off as json dumps will contain " characters - so we really need here ' black
+site_packages = r'''
+__SITE_PACKAGES__
+'''
+
+for site_package in json.loads(site_packages):
+    path = os.path.realpath(os.path.join(os.path.dirname(__file__), site_package))
+    site.addsitedir(path)
+# fmt: on
+
+sys.real_prefix = sys.prefix
+sys.prefix = base
+
+# Move the added items to the front of the path, in place
+new = list(sys.path)
+sys.path[:] = [i for i in new if i not in prev] + [i for i in new if i in prev]