commit 89cd56c1aa8440047f624bcf9596721e5561aab9
author jingwen <jingwen@google.com> Thu Jun 20 05:27:17 2019 -0700
committer Copybara-Service <copybara-worker@google.com> Thu Jun 20 05:28:08 2019 -0700
tree 64db5ce5743801076b7290a43d2d48a26378f74e
parent 4d3c5e22699604fa91fa28b67bb03871b22b7ae1

Make scripts/docs/dot_converter.py Python 3 compatible so //site can be built with Bazel 0.27 without --force_host_python=PY2.

Python 3 changed the type of subprocess#communicate to accept bytes, not str. Change everything else accordingly.

```
$ bazel build //site

# ...

Traceback (most recent call last):
  File "/usr/local/google/home/jingwen/.cache/bazel/_bazel_jingwen/c512c74f287f8aa09b4f3666e26c2b04/sandbox/linux-sandbox/777/execroot/io_bazel/bazel-out/host/bin/scripts/docs/generate_dot_graphs.runfiles/io_bazel/scripts/docs/generate_dot_graphs.py", line 23, in <module>
    converter.convert()
  File "/usr/local/google/home/jingwen/.cache/bazel/_bazel_jingwen/c512c74f287f8aa09b4f3666e26c2b04/sandbox/linux-sandbox/777/execroot/io_bazel/bazel-out/host/bin/scripts/docs/generate_dot_graphs.runfiles/io_bazel/scripts/docs/dot_converter.py", line 42, in convert
    output = dot.communicate(graph)[0].decode()
  File "/usr/lib/python3.6/subprocess.py", line 843, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
  File "/usr/lib/python3.6/subprocess.py", line 1499, in _communicate
    input_view = memoryview(self._input)
TypeError: memoryview: a bytes-like object is required, not 'str'
```

RELNOTES: None.
PiperOrigin-RevId: 254177933

scripts/docs/dot_converter.py

diff --git a/scripts/docs/dot_converter.py b/scripts/docs/dot_converter.py
index c65a15e..75addbf 100644
--- a/scripts/docs/dot_converter.py
+++ b/scripts/docs/dot_converter.py
@@ -28,7 +28,7 @@
 
   def convert(self):
     collect = False
-    graph = ""
+    graph = b""
     block_num = 0
 
     for line in fileinput.input():
@@ -39,18 +39,18 @@
         dot = subprocess.Popen(
             self.dot_command,
             stdin=subprocess.PIPE, stdout=subprocess.PIPE, env=self.dot_env)
-        output = dot.communicate(graph)[0]
+        output = dot.communicate(graph)[0].decode()
         if dot.returncode == 0:
           # cut the first few lines (svg header + comments)
           sys.stdout.write(output.split("\n", 6)[6])
         else:
           sys.stderr.write("inlining block %d failed.\n" % (block_num + 1))
         collect = False
-        graph = ""
+        graph = b""
         block_num += 1
         continue
 
       if collect:
-        graph += line
+        graph += str.encode(line)
       else:
         sys.stdout.write(line)