Notebook: %%time magic makes the variable assignment to be forgotten

[aakhmetz]

If I have a cell magic %%time, then whatever I define in that cell will not be translatted to all other cells.

%%time 
y = 3

and then if I call y in another cell, there will be an error of undefined variable. It works Ok without %%time cell magic.

Please see the gist. I have the latest version of jupyter installed by conda (as of 2019-03-30)

[trvrmcs]

Just encountered this myself - this is a recent breaking change.

[kevin-bates]

This looks like an instance of https://github.com/ipython/ipython/issues/11659 and not a notebook issue itself.

[aakhmetz]

Thank you @kevin-bates! And it looks like the patch will come out soon

[makeyourownalgorithmicart]

I too am seeing this error with %%time

conda list ipython
# packages in environment at /Users/tariq/anaconda3:
#
# Name                    Version                   Build  Channel
ipython                   7.4.0            py37h39e3cac_0  
ipython_genutils          0.2.0                    py37_0  

[sparkingarthur]

same with ipython version 7.4.0

[1JasonZhang]

what time to fix this bug?

[aakhmetz]

following the message from kevin-bates, I think, the bug was fixed. At least, it works for me now

===

# Name                    Version                   Build  Channel
ipython                   7.5.0            py37h39e3cac_0  
ipython_genutils          0.2.0                    py37_0 

[royalosyin]

Reinstall using pip instead of conda on Windows 10. It works now.
pip install ipython -U
pip install ipython_genutils -U

Successfully installed ipython-7.6.1
Successfully installed ipython_genutils-0.2.0

[schneiderfelipe]

Same here, using pip (just updated as @royalosyin suggested, current ipython version is 7.7.0):

In [1]: import numpy as np
In [2]: size = 20
In [3]: D = np.random.rand(size, size)
In [4]: I = np.random.rand(size, size, size, size)
In [5]: %%timeit
   ...: Gloop = np.zeros((size, size))
   ...: for p in range(size):
   ...:     for q in range(size):
   ...:         for r in range(size):
   ...:             for s in range(size):
   ...:                 Gloop[p, q] += (2 * I[p, q, r, s] - I[p, r, q, s]) * D[r, s]
   ...:
234 ms ± 1.07 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
In [6]: Gloop
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-7-b2508f9fc33d> in <module>
----> 1 Gloop

NameError: name 'Gloop' is not defined

I'm using Ubuntu:

% uname -a
Linux mothership 4.15.0-58-generic #64-Ubuntu SMP Tue Aug 6 11:12:41 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
% python3 --version
Python 3.6.8
% pip3 --version
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)
% ipython3 --version
7.7.0

[minda163]

same error......

[aakhmetz]

@schneiderfelipe you code works for me if I use %%time instead of %%timeit (the former is a subject of this thread). I confirm your code does not work with %%timeit. Maybe you can open another issue regarding an unfortunate difference of these two

[dazzle-me]

I just encountered the same problem when I tried to measure the time of some chunk of code in Jupyter. Image can be found here. I tried to access "root_MSE" variable, but no luck :c