We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Improve parsing of result line
The parsing of the input Python to find the last line which will be evaluated (rather than executed) to provide the result is probably a little brittle in certain corner cases.  We should look at what IPython does here and copy that.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `src/pyodide.py`
Content:
```
1 """
2 A library of helper utilities for connecting Python to the browser environment.
3 """
4 
5 from js import XMLHttpRequest
6 
7 import io
8 
9 
10 def open_url(url):
11     """
12     Fetches a given *url* and returns a io.StringIO to access its contents.
13     """
14     req = XMLHttpRequest.new()
15     req.open('GET', url, False)
16     req.send(None)
17     return io.StringIO(req.response)
18 
19 
20 __all__ = ['open_url']
21
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/src/pyodide.py b/src/pyodide.py
--- a/src/pyodide.py
+++ b/src/pyodide.py
@@ -4,6 +4,7 @@
 
 from js import XMLHttpRequest
 
+import ast
 import io
 
 
@@ -17,4 +18,23 @@
     return io.StringIO(req.response)
 
 
-__all__ = ['open_url']
+def eval_code(code, ns):
+    """
+    Runs a string of code, the last part of which may be an expression.
+    """
+    mod = ast.parse(code)
+    if isinstance(mod.body[-1], ast.Expr):
+        expr = ast.Expression(mod.body[-1].value)
+        del mod.body[-1]
+    else:
+        expr = None
+
+    if len(mod.body):
+        exec(compile(mod, '<exec>', mode='exec'), ns, ns)
+    if expr is not None:
+        return eval(compile(expr, '<eval>', mode='eval'), ns, ns)
+    else:
+        return None
+
+
+__all__ = ['open_url', 'eval_code']

{"golden_diff": "diff --git a/src/pyodide.py b/src/pyodide.py\n--- a/src/pyodide.py\n+++ b/src/pyodide.py\n@@ -4,6 +4,7 @@\n \n from js import XMLHttpRequest\n \n+import ast\n import io\n \n \n@@ -17,4 +18,23 @@\n     return io.StringIO(req.response)\n \n \n-__all__ = ['open_url']\n+def eval_code(code, ns):\n+    \"\"\"\n+    Runs a string of code, the last part of which may be an expression.\n+    \"\"\"\n+    mod = ast.parse(code)\n+    if isinstance(mod.body[-1], ast.Expr):\n+        expr = ast.Expression(mod.body[-1].value)\n+        del mod.body[-1]\n+    else:\n+        expr = None\n+\n+    if len(mod.body):\n+        exec(compile(mod, '<exec>', mode='exec'), ns, ns)\n+    if expr is not None:\n+        return eval(compile(expr, '<eval>', mode='eval'), ns, ns)\n+    else:\n+        return None\n+\n+\n+__all__ = ['open_url', 'eval_code']\n", "issue": "Improve parsing of result line\nThe parsing of the input Python to find the last line which will be evaluated (rather than executed) to provide the result is probably a little brittle in certain corner cases.  We should look at what IPython does here and copy that.\n", "before_files": [{"content": "\"\"\"\nA library of helper utilities for connecting Python to the browser environment.\n\"\"\"\n\nfrom js import XMLHttpRequest\n\nimport io\n\n\ndef open_url(url):\n    \"\"\"\n    Fetches a given *url* and returns a io.StringIO to access its contents.\n    \"\"\"\n    req = XMLHttpRequest.new()\n    req.open('GET', url, False)\n    req.send(None)\n    return io.StringIO(req.response)\n\n\n__all__ = ['open_url']\n", "path": "src/pyodide.py"}], "after_files": [{"content": "\"\"\"\nA library of helper utilities for connecting Python to the browser environment.\n\"\"\"\n\nfrom js import XMLHttpRequest\n\nimport ast\nimport io\n\n\ndef open_url(url):\n    \"\"\"\n    Fetches a given *url* and returns a io.StringIO to access its contents.\n    \"\"\"\n    req = XMLHttpRequest.new()\n    req.open('GET', url, False)\n    req.send(None)\n    return io.StringIO(req.response)\n\n\ndef eval_code(code, ns):\n    \"\"\"\n    Runs a string of code, the last part of which may be an expression.\n    \"\"\"\n    mod = ast.parse(code)\n    if isinstance(mod.body[-1], ast.Expr):\n        expr = ast.Expression(mod.body[-1].value)\n        del mod.body[-1]\n    else:\n        expr = None\n\n    if len(mod.body):\n        exec(compile(mod, '<exec>', mode='exec'), ns, ns)\n    if expr is not None:\n        return eval(compile(expr, '<eval>', mode='eval'), ns, ns)\n    else:\n        return None\n\n\n__all__ = ['open_url', 'eval_code']\n", "path": "src/pyodide.py"}]}