allow builtins.help to be missing

Author: Christopher Doris

src/abstract/builtins.jl

@@ -13,8 +13,13 @@ export pyprint
 
 Equivalent to `help(x)` in Python.
 """
-pyhelp() = (pydel!(pybuiltins.help()); nothing)
-pyhelp(x) = (pydel!(pybuiltins.help(x)); nothing)
+function _pyhelp(args...)
+    pyisnone(pybuiltins.help) && error("Python help is not available")
+    pydel!(pybuiltins.help(args...))
+    nothing
+end
+pyhelp() = _pyhelp()
+pyhelp(x) = _pyhelp(x)
 export pyhelp
 
 """

src/concrete/consts.jl

@@ -182,7 +182,14 @@ pybuiltins
 export pybuiltins
 
 for k in BUILTINS
-    push!(INIT_CONSTS_CODE, :(pycopy!(pybuiltins.$k, pybuiltinsmodule.$k)))
+    if k == :help
+        # help is only available in interactive contexts (imported by the 'site' module)
+        # see: https://docs.python.org/3/library/functions.html#help
+        # see: https://github.com/cjdoris/PythonCall.jl/issues/248
+        push!(INIT_CONSTS_CODE, :(pycopy!(pybuiltins.$k, pygetattr(pybuiltinsmodule, $(string(k)), pybuiltins.None))))
+    else
+        push!(INIT_CONSTS_CODE, :(pycopy!(pybuiltins.$k, pygetattr(pybuiltinsmodule, $(string(k))))))
+    end
 end
 
 @eval function init_consts()