Some experimental changes to allow importing Python 3 PyPi packages

python/pip.bzl

@@ -34,6 +34,27 @@ def _pip_import_impl(repository_ctx):
   if result.return_code:
     fail("pip_import failed: %s (%s)" % (result.stdout, result.stderr))
 
+def _pip3_import_impl(repository_ctx):
+  """Core implementation of pip_import."""
+
+  # Add an empty top-level BUILD file.
+  # This is because Bazel requires BUILD files along all paths accessed
+  # via //this/sort/of:path and we wouldn't be able to load our generated
+  # requirements.bzl without it.
+  repository_ctx.file("BUILD", "")
+
+  # To see the output, pass: quiet=False
+  result = repository_ctx.execute([
+    "python3", repository_ctx.path(repository_ctx.attr._script),
+    "--name", repository_ctx.attr.name,
+    "--input", repository_ctx.path(repository_ctx.attr.requirements),
+    "--output", repository_ctx.path("requirements.bzl"),
+    "--directory", repository_ctx.path(""),
+  ])
+
+  if result.return_code:
+    fail("pip_import failed: %s (%s)" % (result.stdout, result.stderr))
+
 pip_import = repository_rule(
     attrs = {
         "requirements": attr.label(
@@ -50,6 +71,22 @@ pip_import = repository_rule(
     implementation = _pip_import_impl,
 )
 
+pip3_import = repository_rule(
+    attrs = {
+        "requirements": attr.label(
+            allow_files = True,
+            mandatory = True,
+            single_file = True,
+        ),
+        "_script": attr.label(
+            executable = True,
+            default = Label("//tools:piptool.par"),
+            cfg = "host",
+        ),
+    },
+    implementation = _pip3_import_impl,
+)
+
 """A rule for importing <code>requirements.txt</code> dependencies into Bazel.
 
 This rule imports a <code>requirements.txt</code> file and generates a new

rules_python/piptool.py

@@ -178,7 +178,7 @@ def whl_library(wheel):
         whl = "@{name}//:{path}",
         requirements = "@{name}//:requirements.bzl",
         extras = [{extras}]
-    )""".format(name=args.name, repo_name=wheel.repository_name(),
+    )""".format(name=args.name, repo_name=_make_wheel_name(args.name, wheel),
                 path=wheel.basename(),
                 extras=','.join([
                   '"%s"' % extra
@@ -187,7 +187,7 @@ def whl_library(wheel):
 
   whl_targets = ','.join([
     ','.join([
-      '"%s": "@%s//:pkg"' % (whl.distribution().lower(), whl.repository_name())
+      '"%s": "@%s//:pkg"' % (whl.distribution().lower(), _make_wheel_name(args.name, whl))
     ] + [
       # For every extra that is possible from this requirements.txt
       '"%s[%s]": "@%s//:%s"' % (whl.distribution().lower(), extra.lower(),
@@ -223,5 +223,8 @@ def requirement(name):
            whl_libraries='\n'.join(map(whl_library, whls)) if whls else "pass",
            mappings=whl_targets))
 
+def _make_wheel_name(namespace, wheel):
+    return "{}_{}".format(namespace, wheel.repository_name())
+
 if __name__ == '__main__':
   main()