Add first version of pyodide.py

Makefile

@@ -144,6 +144,7 @@ root/.built: \
 		src/lazy_import.py \
 		src/sitecustomize.py \
 		src/webbrowser.py \
+		src/pyodide.py \
 		remove_modules.txt
 	rm -rf root
 	mkdir -p root/lib
@@ -154,6 +155,7 @@ root/.built: \
 	cp src/webbrowser.py root/lib/python$(PYMINOR)
 	cp src/_testcapi.py	root/lib/python$(PYMINOR)
 	cp src/pystone.py root/lib/python$(PYMINOR)
+	cp src/pyodide.py root/lib/python$(PYMINOR)/site-packages
 	( \
 		cd root/lib/python$(PYMINOR); \
 		rm -fr `cat ../../../remove_modules.txt`; \

src/pyodide.py

@@ -0,0 +1,17 @@
+# A library of helper utilities for connecting Python to the browser environment
+
+from js import XMLHttpRequest
+
+import io
+
+def open_url(url):
+    """
+    Fetches a given *url* and returns a io.StringIO to access its contents.
+    """
+    req = XMLHttpRequest.new()
+    req.open('GET', url, False)
+    req.send(None)
+    return io.StringIO(req.response)
+
+
+__all__ = ['open_url']

test/data.txt

@@ -0,0 +1 @@
+HELLO

test/test_python.py

@@ -48,6 +48,13 @@ def test_py_proxy(selenium):
     assert selenium.run("hasattr(f, 'baz')") == False
 
 
+
+def test_open_url(selenium):
+    assert selenium.run(
+        "import pyodide\n"
+        "pyodide.open_url('../test/data.txt').read()\n") == 'HELLO\n'
+
+
 def test_run_core_python_test(python_test, selenium):
     selenium.run(
         "import sys\n"