Typos and small fixes

source/etc.rst

@@ -95,7 +95,7 @@ The exact mechanism had two major drawbacks:
 * Bytecode is not compatible across Python versions.
   If the same module was being imported by different versions of Python,
   each would overwrite the ``.pyc`` file with its own flavor of bytecode on
-  import. This would invalidating the cache for all other versions.
+  import. This would invalidate the cache for all other versions.
 * The ``.pyc`` cache could be used even without a corresponding ``.py`` file,
   which allowed some space saving (by distributing only the compiled file).
   However, if one deleted a ``.py`` file but forgot to also remove the ``.pyc``,

source/process.rst

@@ -150,5 +150,5 @@ Python 3-compatible version.
 For less conservative projects, dropping Python 2 support will include
 removing compatibility workarounds.
 
-Targetting Python 3 only this will enable you start using all the new
+Targeting Python 3 only will enable you start using all the new
 features in the new major version – but those are for another guide.

source/strings.rst

@@ -257,7 +257,7 @@ results), while a Python 3 version will involve more thought and code.
 
 You might discover mistakes in how the Python 2 version processes strings.
 In these cases, it might be a good idea to enable new tests for Python 3 only:
-if some bugs in edge casessurvived so far, they can probably live until
+if some bugs in edge cases survived so far, they can probably live until
 Python 2 is retired. Apply your own judgement.
 
 Things to test follow.