go.nil must be explicitly initialized in go.py -- just doing nil = GoClass() doesn't do it.

Author: Randall C. O'Reilly

README.md

@@ -17,14 +17,15 @@ New features:
 
 ## Installation
 
-Currently using [pybindgen](https://pybindgen.readthedocs.io/en/latest/tutorial/) to generate the low-level c-to-python bindings, but support for [cffi](https://cffi.readthedocs.io/en/latest/) should be relatively straightforward for those using PyPy instead of CPython (pybindgen should be significantly faster for CPython apparently).  
+Currently using [pybindgen](https://pybindgen.readthedocs.io/en/latest/tutorial/) to generate the low-level c-to-python bindings, but support for [cffi](https://cffi.readthedocs.io/en/latest/) should be relatively straightforward for those using PyPy instead of CPython (pybindgen should be significantly faster for CPython apparently).  You also need `goimports` to ensure the correct imports are included.
 
 ```sh
 $ python3 -m pip install pybindgen
+$ go get golang.org/x/tools/cmd/goimports
 $ go get github.com/go-python/gopy
 ```
 
-You will need `Go >= 1.5` (no reason not to use the most recent version).
+(This all assumes you have already installed [Go itself](https://golang.org/doc/install), and added `~/go/bin` to your `PATH`).
 
 To [install python modules](https://packaging.python.org/tutorials/packaging-projects/), you will need the python install packages:
 

bind/gen.go

@@ -236,6 +236,13 @@ class GoClass(object):
 # use go.nil for nil pointers 
 nil = GoClass()
 
+# need to explicitly initialize it
+def main():
+	global nil
+	nil = GoClass()
+
+main()
+
 def Init():
 	"""calls the GoPyInit function, which runs the 'main' code string that was passed using -main arg to gopy"""
 	_%[1]s.GoPyInit()