Merge pull request #11716 from Pragnya02/fix_magic_time

Fix magic time

IPython/core/displayhook.py

@@ -298,7 +298,7 b' class DisplayHook(Configurable):'
         self._, self.__, self.___ = '', '', ''
 
         if '_' not in builtin_mod.__dict__:
-            self.shell.user_ns.update({'_':None,'__':None, '___':None})
+            self.shell.user_ns.update({'_':self._,'__':self.__,'___':self.___})
         import gc
         # TODO: Is this really needed?
         # IronPython blocks here forever

IPython/core/magics/execution.py

@@ -49,6 +49,14 b' from warnings import warn'
 from logging import error
 from io import StringIO
 
+if sys.version_info > (3,8):
+    from ast import Module
+else :
+    # mock the new API, ignore second argument
+    # see https://github.com/ipython/ipython/issues/11590
+    from ast import Module as OriginalModule
+    Module = lambda nodelist, type_ignores: OriginalModule(nodelist)
+
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
@@ -1261,6 +1269,7 b' python-profiler package from non-free.""")'
         # Minimum time above which compilation time will be reported
         tc_min = 0.1
 
+        expr_val=None
         if len(expr_ast.body)==1 and isinstance(expr_ast.body[0], ast.Expr):
             mode = 'eval'
             source = '<timed eval>'
@@ -1268,6 +1277,15 b' python-profiler package from non-free.""")'
         else:
             mode = 'exec'
             source = '<timed exec>'
+            # multi-line %%time case
+            if len(expr_ast.body) > 1 :
+                expr_val=expr_ast.body[-1]
+                code_val = self.shell.compile(ast.Expression(expr_val.value)
+                                                , '<timed eval>'
+                                                , 'eval')
+                expr_ast=expr_ast.body[:-1]
+                expr_ast = Module(expr_ast, [])
+
         t0 = clock()
         code = self.shell.compile(expr_ast, source, mode)
         tc = clock()-t0
@@ -1289,11 +1307,15 b' python-profiler package from non-free.""")'
             st = clock2()
             try:
                 exec(code, glob, local_ns)
+                out=None
+                # multi-line %%time case
+                if expr_val and isinstance(expr_val, ast.Expr):
+                    out = eval(code_val, glob, local_ns)  
             except:
                 self.shell.showtraceback()
                 return
             end = clock2()
-            out = None
+
         wall_end = wtime()
         # Compute actual times and report
         wall_time = wall_end-wall_st

IPython/core/tests/test_magic.py

@@ -9,6 +9,7 b' import os'
 import re
 import sys
 import warnings
+from textwrap import dedent
 from unittest import TestCase
 from importlib import invalidate_caches
 from io import StringIO
@@ -419,6 +420,19 b' def test_time3():'
                     "run = 0\n"
                     "run += 1")
 
+def test_multiline_time():
+    """Make sure last statement from time return a value."""
+    ip = get_ipython()
+    ip.user_ns.pop('run', None)
+
+    ip.run_cell(dedent("""\
+        %%time
+        a = "ho"
+        b = "hey"
+        a+b
+        """))
+    nt.assert_equal(ip.user_ns_hidden['_'], 'hohey')
+
 def test_time_local_ns():
     """
     Test that local_ns is actually global_ns when running a cell magic