Update Python docs and messages to refer to @rules_python

This replaces some uses of @bazel_tools//tools/python/... in user-visible strings with the appropriate @rules_python-based paths.

Work toward #8893.

RELNOTES: None
PiperOrigin-RevId: 261197893

src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPyRuleClasses.java

@@ -119,7 +119,7 @@ executable Python rule (<code>py_binary</code> or <code>py_test</code>).
           you can run the <code>find_requirements</code> aspect on your target:
           <pre>
           bazel build &lt;your target&gt; \
-              --aspects=@bazel_tools//tools/python:srcs_version.bzl%find_requirements \
+              --aspects=@rules_python//python:defs.bzl%find_requirements \
               --output_groups=pyversioninfo
           </pre>
           This will build a file with the suffix <code>-pyversioninfo.txt</code> giving information
@@ -195,8 +195,8 @@ is always set (possibly by default) to whatever version is specified by this att
           this one.
 
           <p>If you want to <code>select()</code> on the current Python version, you can inspect the
-          value of <code>@bazel_tools//tools/python:python_version</code>. See
-          <a href="https://github.com/bazelbuild/bazel/blob/4b74ea9a3f81b7ed30562f1689827b5488884c86/tools/python/BUILD#L33">here</a>
+          value of <code>@rules_python//python:python_version</code>. See
+          <a href="https://github.com/bazelbuild/rules_python/blob/120590e2f2b66e5590bf4dc8ebef9c5338984775/python/BUILD#L43">here</a>
           for more information.
 
           <p><b>Bug warning:</b> This attribute sets the version for which Bazel builds your target,

tools/python/BUILD.tools

@@ -1,3 +1,15 @@
+################################################################################
+# DEPRECATION WARNING                                                          #
+#                                                                              #
+# Direct access to @bazel_tools//tools/python, and to the native Python rules  #
+# and providers, is deprecated. All of these symbols are now accessible from   #
+# bazelbuild/rules_python.                                                     #
+#                                                                              #
+# For native rules in particular, --incompatible_load_python_rules_from_bzl    #
+# (#9006) prohibits direct access to the native rules, and will be flipped on  #
+# in Bazel 1.0.                                                                #
+################################################################################
+
 load(":python_version.bzl", "define_python_version_flag")
 load(":toolchain.bzl", "define_autodetecting_toolchain")
 

tools/python/pywrapper_template.txt

@@ -12,11 +12,11 @@ STRICT="%STRICT%"
 if [ "$STRICT" = "1" ]; then
   FAILURE_HEADER="\
 Error occurred while attempting to use the default Python toolchain \
-(@bazel_tools//tools/python:autodetecting_toolchain)."
+(@rules_python//python:autodetecting_toolchain)."
 else
   FAILURE_HEADER="\
 Error occurred while attempting to use the non-strict autodetecting Python \
-toolchain (@bazel_tools//tools/python:autodetecting_toolchain_nonstrict)."
+toolchain (@rules_python//python:autodetecting_toolchain_nonstrict)."
 fi
 
 die() {
@@ -60,7 +60,7 @@ $PATH
 Please ensure an interpreter is available on this platform (and marked \
 executable), or else register an appropriate Python toolchain as per the \
 documentation for py_runtime_pair \
-(https://github.com/bazelbuild/bazel/blob/master/tools/python/toolchain.bzl)."
+(https://github.com/bazelbuild/rules_python/blob/master/docs/python.md#py_runtime_pair)."
 fi
 
 if [ "$STRICT" = "1" ]; then
@@ -76,15 +76,15 @@ $PATH
 Please ensure an interpreter with version %VERSION% is available on this \
 platform as 'python%VERSION%' or 'python', or else register an appropriate \
 Python toolchain as per the documentation for py_runtime_pair \
-(https://github.com/bazelbuild/bazel/blob/master/tools/python/toolchain.bzl).
+(https://github.com/bazelbuild/rules_python/blob/master/docs/python.md#py_runtime_pair).
 
 Note that prior to Bazel 0.27, there was no check to ensure that the \
 interpreter's version matched the version declared by the target (#4815). If \
 your build worked prior to Bazel 0.27, and you're sure your targets do not \
 require Python %VERSION%, you can opt out of this version check by using the \
 non-strict autodetecting toolchain instead of the standard autodetecting \
 toolchain. This can be done by passing the flag \
-\`--extra_toolchains=@bazel_tools//tools/python:autodetecting_toolchain_nonstrict\` \
+\`--extra_toolchains=@rules_python//python:autodetecting_toolchain_nonstrict\` \
 on the command line or adding it to your bazelrc."
   fi
 fi

tools/python/runfiles/runfiles.py

@@ -20,12 +20,12 @@
       py_binary(
           name = "my_binary",
           ...
-          deps = ["@bazel_tools//tools/python/runfiles"],
+          deps = ["@rules_python//python/runfiles"],
       )
 
 2.  Import the runfiles library.
 
-      from bazel_tools.tools.python.runfiles import runfiles
+      from rules_python.python.runfiles import runfiles
 
 3.  Create a Runfiles object and use rlocation to look up runfile paths:
 
@@ -49,7 +49,7 @@
     the right environment variables for them:
 
       import subprocess
-      from bazel_tools.tools.python.runfiles import runfiles
+      from rules_python.python.runfiles import runfiles
 
       r = runfiles.Create()
       env = {}

tools/python/srcs_version.bzl

@@ -281,7 +281,7 @@ find_requirements = aspect(
 The aspect definition. Can be invoked on the command line as
 
     bazel build //pkg:my_py_binary_target \
-        --aspects=@bazel_tools//tools/python:srcs_version.bzl%find_requirements \
+        --aspects=@rules_python//python:defs.bzl%find_requirements \
         --output_groups=pyversioninfo
 """,
 )

tools/python/toolchain.bzl

@@ -77,7 +77,7 @@ Example usage:
 ```python
 # In your BUILD file...
 
-load("@bazel_tools//tools/python:toolchain.bzl", "py_runtime_pair")
+load("@rules_python//python:defs.bzl", "py_runtime_pair")
 
 py_runtime(
     name = "my_py2_runtime",
@@ -101,7 +101,7 @@ toolchain(
     name = "my_toolchain",
     target_compatible_with = <...>,
     toolchain = ":my_py_runtime_pair",
-    toolchain_type = "@bazel_tools//tools/python:toolchain_type",
+    toolchain_type = "@rules_python//python:toolchain_type",
 )
 ```