Ran black, reverted changes on utils/io.py.

IPython/utils/io.py

@@ -14,7 +14,6 b' import sys'
 import tempfile
 import warnings
 from warnings import warn
-from pathlib import Path
 
 from IPython.utils.decorators import undoc
 from .capture import CapturedIO, capture_output
@@ -205,11 +204,11 b" def temp_pyfile(src, ext='.py'):"
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
-    fname = Path(tempfile.mkstemp(ext)[1])
-    with fname.open('w') as f:
+    fname = tempfile.mkstemp(ext)[1]
+    with open(fname,'w') as f:
         f.write(src)
         f.flush()
-    return str(fname)
+    return fname
 
 @undoc
 def atomic_writing(*args, **kwargs):