From 656e185c6a6caaa72b20e164141f2a7577b0e7eb Mon Sep 17 00:00:00 2001
From: anatoly techtonik <techtonik@gmail.com>
Date: Sun, 11 Nov 2018 19:24:37 +0300
Subject: [PATCH 1/2] Simplify version parsing example

This removes regexp and adds `import os`.

File is read in `cp437` because this encoding has no missing code points while converting to `utf-8` string. Only ASCII set is used anyways.
---
 .../single-sourcing-package-version.rst       | 38 ++++++++-----------
 1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/source/guides/single-sourcing-package-version.rst b/source/guides/single-sourcing-package-version.rst
index 19e9a21e7..d141b4d01 100644
--- a/source/guides/single-sourcing-package-version.rst
+++ b/source/guides/single-sourcing-package-version.rst
@@ -8,34 +8,28 @@ Single-sourcing the package version
 There are many techniques to maintain a single source of truth for the version
 number of your project:
 
-#.  Read the file in :file:`setup.py` and parse the version with a regex.
-    Example ( from `pip setup.py
-    <https://github.com/pypa/pip/blob/master/setup.py#L12>`_)::
-
-        here = os.path.abspath(os.path.dirname(__file__))
-
-        def read(*parts):
-            with codecs.open(os.path.join(here, *parts), 'r') as fp:
-                return fp.read()
-
-        def find_version(*file_paths):
-            version_file = read(*file_paths)
-            version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]",
-                                      version_file, re.M)
-            if version_match:
-                return version_match.group(1)
-            raise RuntimeError("Unable to find version string.")
+#.  Read the file with version info in :file:`setup.py` and parse version line.
+    Example::
+
+        import os
+
+        def get_version(rel_path):
+            current_dir = os.path.abspath(os.path.dirname(__file__))
+            version_file = os.path.join(current_dir, rel_path)
+            for line in open(version_file, 'rb'):
+                # Decode to unicode for PY2/PY3 in a fail-safe way
+                line = line.decode('cp437')
+                if line.startswith('__version__'):
+                    # __version__ = "0.9"
+                    delim = '\"' if '\"' in line else '\''
+                    return line.split(delim)[1]
 
         setup(
            ...
-           version=find_version("package", "__init__.py")
+           version=get_version("package/__init__.py"),
            ...
         )
 
-    .. note::
-
-        This technique has the disadvantage of having to deal with complexities of regular expressions.
-
 #.  Use an external build tool that either manages updating both locations, or
     offers an API that both locations can use.
 

From 7d7a1713cebfe5c2d9c162ff80678f9c4a6e863d Mon Sep 17 00:00:00 2001
From: anatoly techtonik <techtonik@gmail.com>
Date: Mon, 26 Nov 2018 10:06:48 +0300
Subject: [PATCH 2/2] Parse __version__ file as binary

To avoid problems with unknown encoding, file with __version__
is processed as binary and the final number is converted to string
just before the function returns.
---
 source/guides/single-sourcing-package-version.rst | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/source/guides/single-sourcing-package-version.rst b/source/guides/single-sourcing-package-version.rst
index d141b4d01..f597d2a62 100644
--- a/source/guides/single-sourcing-package-version.rst
+++ b/source/guides/single-sourcing-package-version.rst
@@ -17,12 +17,10 @@ number of your project:
             current_dir = os.path.abspath(os.path.dirname(__file__))
             version_file = os.path.join(current_dir, rel_path)
             for line in open(version_file, 'rb'):
-                # Decode to unicode for PY2/PY3 in a fail-safe way
-                line = line.decode('cp437')
-                if line.startswith('__version__'):
+                if line.startswith(b'__version__'):
                     # __version__ = "0.9"
-                    delim = '\"' if '\"' in line else '\''
-                    return line.split(delim)[1]
+                    delim = b'\"' if b'\"' in line else b'\''
+                    return line.split(delim)[1].decode()
 
         setup(
            ...