tqdm.auto errors in notebooks if ipywidgets is not installed

[ivirshup]

• I have marked all applicable categories:
  • exception-raising bug
  • visual output bug
  • documentation request (i.e. "X is missing from the documentation." If instead I want to ask "how to use X?" I understand [StackOverflow#tqdm] is more appropriate)
  • new feature request
• I have visited the [source website], and in particular
  read the [known issues]
• I have searched through the [issue tracker] for duplicates
• I have mentioned version numbers, operating system and
  environment, where applicable:

  import tqdm, sys
  print(tqdm.__version__, sys.version, sys.platform)

4.51.0 3.8.5 (default, Sep  4 2020, 02:22:02) 
[Clang 10.0.0 ] darwin

Example

Created a conda environment with:

$ conda create -yn tqdm_nowidgets python=3.8 tqdm ipython notebook

Using that environment, in a notebook:

from tqdm.auto import tqdm
from time import sleep

for i in tqdm(range(100)):
    sleep(0.05)

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-3-542c7d78a2ff> in <module>
----> 1 for i in tqdm(range(100)):
      2     sleep(0.05)

~/miniconda3/envs/tqdm_nowidgets/lib/python3.8/site-packages/tqdm/notebook.py in __init__(self, *args, **kwargs)
    221         unit_scale = 1 if self.unit_scale is True else self.unit_scale or 1
    222         total = self.total * unit_scale if self.total else self.total
--> 223         self.container = self.status_printer(
    224             self.fp, total, self.desc, self.ncols)
    225         self.sp = self.display

~/miniconda3/envs/tqdm_nowidgets/lib/python3.8/site-packages/tqdm/notebook.py in status_printer(_, total, desc, ncols)
     94         # Prepare IPython progress bar
     95         if IProgress is None:  # #187 #451 #558 #872
---> 96             raise ImportError(
     97                 "IProgress not found. Please update jupyter and ipywidgets."
     98                 " See https://ipywidgets.readthedocs.io/en/stable"

ImportError: IProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html

output of conda list

# packages in environment at /Users/isaac/miniconda3/envs/tqdm_nowidgets:
#
# Name                    Version                   Build  Channel
appnope                   0.1.0                 py38_1001  
argon2-cffi               20.1.0           py38haf1e3a3_1  
async_generator           1.10                       py_0  
attrs                     20.3.0             pyhd3eb1b0_0  
backcall                  0.2.0                      py_0  
bleach                    3.2.1                      py_0  
ca-certificates           2020.10.14                    0  
certifi                   2020.11.8        py38hecd8cb5_0  
cffi                      1.14.3           py38h2125817_2  
decorator                 4.4.2                      py_0  
defusedxml                0.6.0                      py_0  
entrypoints               0.3                      py38_0  
importlib-metadata        2.0.0                      py_1  
importlib_metadata        2.0.0                         1  
ipykernel                 5.3.4            py38h5ca1d4c_0  
ipython                   7.19.0           py38h01d92e1_0  
ipython_genutils          0.2.0                    py38_0  
jedi                      0.17.2                   py38_0  
jinja2                    2.11.2                     py_0  
jsonschema                3.2.0                      py_2  
jupyter_client            6.1.7                      py_0  
jupyter_core              4.7.0            py38hecd8cb5_0  
jupyterlab_pygments       0.1.2                      py_0  
libcxx                    10.0.0                        1  
libedit                   3.1.20191231         h1de35cc_1  
libffi                    3.3                  hb1e8313_2  
libsodium                 1.0.18               h1de35cc_0  
markupsafe                1.1.1            py38h1de35cc_1  
mistune                   0.8.4           py38h1de35cc_1001  
nbclient                  0.5.1                      py_0  
nbconvert                 6.0.7                    py38_0  
nbformat                  5.0.8                      py_0  
ncurses                   6.2                  h0a44026_1  
nest-asyncio              1.4.3              pyhd3eb1b0_0  
notebook                  6.1.4                    py38_0  
openssl                   1.1.1h               haf1e3a3_0  
packaging                 20.4                       py_0  
pandoc                    2.11                 h0dc7051_0  
pandocfilters             1.4.3            py38hecd8cb5_1  
parso                     0.7.0                      py_0  
pexpect                   4.8.0              pyhd3eb1b0_3  
pickleshare               0.7.5                 py38_1001  
pip                       20.2.4           py38hecd8cb5_0  
prometheus_client         0.8.0                      py_0  
prompt-toolkit            3.0.8                      py_0  
ptyprocess                0.6.0              pyhd3eb1b0_2  
pycparser                 2.20                       py_2  
pygments                  2.7.2              pyhd3eb1b0_0  
pyparsing                 2.4.7                      py_0  
pyrsistent                0.17.3           py38haf1e3a3_0  
python                    3.8.5                h26836e1_1  
python-dateutil           2.8.1                      py_0  
pyzmq                     19.0.2           py38hb1e8313_1  
readline                  8.0                  h1de35cc_0  
send2trash                1.5.0                    py38_0  
setuptools                50.3.1           py38hecd8cb5_1  
six                       1.15.0           py38hecd8cb5_0  
sqlite                    3.33.0               hffcf06c_0  
terminado                 0.9.1                    py38_0  
testpath                  0.4.4                      py_0  
tk                        8.6.10               hb0a8c7a_0  
tornado                   6.0.4            py38h1de35cc_1  
tqdm                      4.51.0             pyhd3eb1b0_0  
traitlets                 5.0.5                      py_0  
wcwidth                   0.2.5                      py_0  
webencodings              0.5.1                    py38_1  
wheel                     0.35.1             pyhd3eb1b0_0  
xz                        5.2.5                h1de35cc_0  
zeromq                    4.3.3                hb1e8313_3  
zipp                      3.4.0              pyhd3eb1b0_0  
zlib                      1.2.11               h1de35cc_3  

pic

Why this is a problem

I would like my package to have nice progress bars wherever it's used, and not error because of them. I don't want any notebook related as dependencies for my package. I think it makes sense for tqdm.auto to make a choice which will not error.

This issue has come up a few times elsewhere

• https://stackoverflow.com/questions/53247985/tqdm-4-28-1-in-jupyter-notebook-intprogress-not-found-please-update-jupyter-an
• Use tqdm instead of tqdm.auto when downloading datasets scverse/scanpy#1130

What I think should happen

If ipywidgets is not available, from tqdm.auto import tqdm should not import a tqdm class that relies on ipywidgets. It could just import tqdm.tqdm.

[bdice]

This bug also causes an error when using any of the "contrib" features in a notebook without ipywidgets. All the iterables like tmap, tzip, tenumerate and concurrency features like process_map and thread_map accept an argument tqdm_class that defaults to tqdm.auto.tqdm. However, using that automatic class results in a traceback like the following if ipywidgets is unavailable when running in a notebook. I can confirm that #1218 fixes this bug. (Note that #1148 fixed a related issue with passing tqdm_class to tmap / tzip.)

[...]
--> 377 return list(tmap(func, iterable, **kwargs))

File .../python3.9/site-packages/tqdm/contrib/__init__.py:97, in tmap(function, *sequences, **tqdm_kwargs)
     88 @builtin_iterable
     89 def tmap(function, *sequences, **tqdm_kwargs):
     90     """
     91     Equivalent of builtin `map`.
     92 
   (...)
     95     tqdm_class  : [default: tqdm.auto.tqdm].
     96     """
---> 97     for i in tzip(*sequences, **tqdm_kwargs):
     98         yield function(*i)

File .../python3.9/site-packages/tqdm/contrib/__init__.py:84, in tzip(iter1, *iter2plus, **tqdm_kwargs)
     82 kwargs = tqdm_kwargs.copy()
     83 tqdm_class = kwargs.pop("tqdm_class", tqdm_auto)
---> 84 for i in zip(tqdm_class(iter1, **kwargs), *iter2plus):
     85     yield i

File .../python3.9/site-packages/tqdm/notebook.py:242, in tqdm_notebook.__init__(self, *args, **kwargs)
    240 unit_scale = 1 if self.unit_scale is True else self.unit_scale or 1
    241 total = self.total * unit_scale if self.total else self.total
--> 242 self.container = self.status_printer(self.fp, total, self.desc, self.ncols)
    243 self.container.pbar = proxy(self)
    244 self.displayed = False

File .../python3.9/site-packages/tqdm/notebook.py:115, in tqdm_notebook.status_printer(_, total, desc, ncols)
    106 # Fallback to text bar if there's no total
    107 # DEPRECATED: replaced with an 'info' style bar
    108 # if not total:
   (...)
    112 
    113 # Prepare IPython progress bar
    114 if IProgress is None:  # #187 #451 #558 #872
--> 115     raise ImportError(
    116         "IProgress not found. Please update jupyter and ipywidgets."
    117         " See https://ipywidgets.readthedocs.io/en/stable"
    118         "/user_install.html")
    119 if total:
    120     pbar = IProgress(min=0, max=total)

ImportError: IProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html

[casperdcl]

Even though the error is raised by design, given the number of people who expect different behaviour - probably worth a graceful fallback indeed (with a warning rather than an error).

[casperdcl]

Sorry for the massive delay in reviewing. Addressed in v4.63.0 :)