PYTHON-2668 Improve README installation instructions and add FAQ (#34)

Author: prashantmital

bindings/python/README.rst

@@ -42,11 +42,23 @@ suited for in-memory analytical processing applications.
 
 Installing PyMongoArrow
 =======================
-PyMongoArrow is available on PyPI:::
+PyMongoArrow is available on PyPI::
 
   $ python -m pip install pymongoarrow
 
-PyMongoArrow wheels are available for macOS and Linux on x86_64 architectures.
+To use PyMongoArrow with MongoDB Atlas' ``mongodb+srv://`` URIs, you will
+need to also install PyMongo with the ``srv`` extra::
+
+  $ python -m pip install 'pymongo[srv]<4' pymongoarrow
+
+To use PyMongoArrow APIs that return query result sets as pandas
+DataFrame instances, you will also need to have the ``pandas`` package
+installed::
+
+     $ python -m pip install pandas
+
+Currently, PyMongoArrow wheels are only available for macOS and Linux
+on x86_64 architectures.
 
 Documentation
 =============

bindings/python/docs/source/faq.rst

@@ -0,0 +1,15 @@
+Frequently Asked Questions
+==========================
+
+.. contents::
+
+Why do I get ``ModuleNotFoundError: No module named 'pandas'`` when using PyMongoArrow
+--------------------------------------------------------------------------------------
+
+This error is raised when an application attempts to use a PyMongoArrow API
+that returns query result sets as a :class:`pandas.DataFrame` instance without
+having ``pandas`` installed in the Python environment. Since ``pandas`` is not
+a direct dependency of PyMongoArrow, it is not automatically installed when
+you install ``pymongoarrow`` and must be installed separately::
+
+  $ python -m pip install pandas

bindings/python/docs/source/index.rst

@@ -21,6 +21,9 @@ know to use **PyMongoArrow**.
 :doc:`supported_types`
   A list of BSON types that are supported by PyMongoArrow.
 
+:doc:`faq`
+  Frequently asked questions.
+
 :doc:`api/index`
   The complete API documentation, organized by module.
 

bindings/python/docs/source/installation.rst

@@ -24,7 +24,7 @@ on all platforms::
 
 To get a specific version of pymongo::
 
-  $ python -m pip install pymongoarrow==0.1.0
+  $ python -m pip install pymongoarrow==0.1.1
 
 To upgrade using pip::
 
@@ -58,8 +58,13 @@ For example, to use PyMongoArrow with MongoDB Atlas' ``mongodb+srv://`` URIs
 users must install PyMongo with the ``srv`` extra in addition to installing
 PyMongoArrow::
 
-  $ python -m pip install pymongoarrow
-  $ python -m pip install pymongo[srv]>=3.11,<4
+  $ python -m pip install 'pymongo[srv]<4' pymongoarrow
+
+Applications intending to use PyMongoArrow APIs that return query result sets
+as :class:`pandas.DataFrame` instances (e.g. :meth:`~pymongoarrow.api.find_pandas_all`)
+must also have ``pandas`` installed::
+
+  $ python -m pip install pandas
 
 Installing from source
 ----------------------