Use pathlib in edit magic

IPython/core/magics/code.py

@@ -22,6 +22,7 b' import ast'
 from itertools import chain
 from urllib.request import urlopen
 from urllib.parse import urlencode
+from pathlib import Path
 
 # Our own packages
 from IPython.core.error import TryNext, StdinNotImplementedError, UsageError
@@ -688,11 +689,14 b' class CodeMagics(Magics):'
         # do actual editing here
         print('Editing...', end=' ')
         sys.stdout.flush()
+        filepath = Path(filename)
         try:
-            # Quote filenames that may have spaces in them
-            if ' ' in filename:
-                filename = "'%s'" % filename
-            self.shell.hooks.editor(filename,lineno)
+            # Quote filenames that may have spaces in them when opening
+            # the editor
+            quoted = filename = str(filepath.absolute())
+            if ' ' in quoted:
+                quoted = "'%s'" % quoted
+            self.shell.hooks.editor(quoted,lineno)
         except TryNext:
             warn('Could not open editor')
             return
@@ -700,7 +704,7 b' class CodeMagics(Magics):'
         # XXX TODO: should this be generalized for all string vars?
         # For now, this is special-cased to blocks created by cpaste
         if args.strip() == 'pasted_block':
-            with open(filename, 'r') as f:
+            with filepath.open('r') as f:
                 self.shell.user_ns['pasted_block'] = f.read()
 
         if 'x' in opts:  # -x prevents actual execution
@@ -711,7 +715,7 b' class CodeMagics(Magics):'
                 if not is_temp:
                     self.shell.user_ns['__file__'] = filename
                 if 'r' in opts:    # Untranslated IPython code
-                    with open(filename, 'r') as f:
+                    with filepath.open('r') as f:
                         source = f.read()
                     self.shell.run_cell(source, store_history=False)
                 else:
@@ -720,10 +724,10 b' class CodeMagics(Magics):'
 
         if is_temp:
             try:
-                with open(filename) as f:
+                with filepath.open() as f:
                     return f.read()
             except IOError as msg:
-                if msg.filename == filename:
+                if Path(msg.filename) == filepath:
                     warn('File not found. Did you forget to save?')
                     return
                 else:

IPython/core/tests/test_magic.py

@@ -1138,6 +1138,11 b' def test_edit_cell():'
     # test
     _run_edit_test("1", exp_contents=ip.user_ns['In'][1], exp_is_temp=True)
 
+def test_edit_fname():
+    """%edit file"""
+    # test
+    _run_edit_test("test file.py", exp_filename="test file.py")
+
 def test_bookmark():
     ip = get_ipython()
     ip.run_line_magic('bookmark', 'bmname')