Fix minor spelling, grammar, and consistency errors in the Packages section.

Author: GloryFish

docs/writing/structure.rst

@@ -149,29 +149,29 @@ Packages
 Python provides a very straightforward packaging system, which is simply an
 extension of the module mechanism to a directory.
 
-Any directory with a __init__.py file is considered a Python package. The
+Any directory with an __init__.py file is considered a Python package. The
 different modules in the package are imported in a similar manner as plain
-modules, will a special behavior for the __init__.py file, that is used to
+modules, but with a special behavior for the __init__.py file, which is used to
 gather all package-wide definitions.
 
 A file modu.py in the directory pack/ is imported with the statement `import
-pack.modu`. This statement will look for a __init__.py file in `pack`, execute
-all its top-level statements. Then it will look for a file `pack/modu.py` and
-execute all its top-level statements. After these operations, any variable,
-function or class defined in modu.py is available in pack.modu namespace.
+pack.modu`. This statement will look for an __init__.py file in `pack`, execute
+all of its top-level statements. Then it will look for a file `pack/modu.py` and
+execute all of its top-level statements. After these operations, any variable,
+function, or class defined in modu.py is available in the pack.modu namespace.
 
-A commonly seen issue is to add too many code and functions in __init__.py
+A commonly seen issue is to add too much code to __init__.py
 files. When the project complexity grows, there may be sub-packages and
-sub-sub-packages in a deep directory structure, and then, import a single item
-from a sub-sub-package will require to execute all __init__.py file met while
-descending the tree.
+sub-sub-packages in a deep directory structure, and then, importing a single item
+from a sub-sub-package will require executing all __init__.py files met while
+traversing the tree.
 
-Leaving a __init__.py file empty is considered normal and even a good pratice,
+Leaving an __init__.py file empty is considered normal and even a good practice,
 if the package's modules and sub-packages do not need to share any code.
 
 Lastly, a convenient syntax is available for importing deeply nested packages:
-`import very.deep.module as mod` allow to use `mod` in place of the verbose
-repetition of `very.deep.module` in front of each calls to module items.
+`import very.deep.module as mod`. This allows you to use `mod` in place of the verbose
+repetition of `very.deep.module`.
 
 Object-oriented programming
 ---------------------------