How to get progress bar with tqdm in a for loop over directory - for-loop

Question

I am trying to conditionally load some files from a directory. I would like to have a progress bar from tqdm on the process. I currently running this:
loaddir = r'D:\Folder'
# loop the files in the directory
print('Data load initiated')
for subdir, dirs, files in os.walk(loaddir_res):
for name in tqdm(files):
if name.startswith('Test'):
#do things
which gives
Data load initiated
0%| | 0/6723 [00:00<?, ?it/s]
0%| | 26/6723 [00:00<00:28, 238.51it/s]
1%| | 47/6723 [00:00<00:31, 213.62it/s]
1%| | 72/6723 [00:00<00:30, 220.84it/s]
1%|▏ | 91/6723 [00:00<00:31, 213.59it/s]
2%|▏ | 115/6723 [00:00<00:30, 213.73it/s]
This has two problems:
When progress is updated a new line appears in my IPython console in Spyder
I am actually timing the loop over the files and not over the files that start with 'Test' and therefore progress and remaining time are not accurate.
However, if I try this:
loaddir = r'D:\Folder'
# loop the files in the directory
print('Data load initiated')
for subdir, dirs, files in os.walk(loaddir_res):
for name in files:
if tqdm(name.startswith('Test')):
#do things
I get the following error.
Traceback (most recent call last):
File "<ipython-input-80-b801165d4cdb>", line 21, in <module>
if tqdm(name.startswith('Probe')):
TypeError: 'NoneType' object cannot be interpreted as an integer
I would like to have a progress bar in only one line that updates whenever the startswith loop is activated.
----UPDATE----
I also found out here that it can also be used like this:
files = [f for f in tqdm(files) if f.startswith('Test')]
Which allows to track progress with list comprehension by wrapping the iterable with tqdm. However in spyder this results in a separate line for each progress update.
----UPDATE2----
It actually works fine in spyder. Sometimes if the loop fails, it might go back to printing one line of progress update. But i haven't seen this very often after the latest updates.

Answer 1

firstly the answer:
loaddir = r'D:\surfdrive\COMSOL files\Batch folder\Current batch simulation files'
# loop the files in the directory
print('Data load initiated')
for subdir, dirs, files in os.walk(loaddir_res):
files = [f for f in files if f.startswith('Test')]
for name in tqdm(files):
#do things
This will work in any decent environment (including a bare terminal). The solution is to not give tqdm the unused filenames. You may find https://github.com/tqdm/tqdm/wiki/How-to-make-a-great-Progress-Bar insightful.
Secondly the issue with multiple lines output is well-known and due to some environments being broken (https://github.com/tqdm/tqdm#faq-and-known-issues) by not supporting carriage return (\r).
The correct links for this problem in Spyder are https://github.com/tqdm/tqdm/issues/512 and https://github.com/spyder-ide/spyder/issues/6172

Answer 2

(Spyder maintainer here) This is a known limitation of TQDM progress bars in Spyder. I'd recommend you to open an issue about it in its Github repository.

Answer 3

Specify position=0 and leave=True like this:
for i in tqdm(range(10), position=0, leave=True):
# Some code
Or in a list comprehension:
nums = [i for i in tqdm(range(10), position=0, leave=True)]
It's worth to mention that you can set `position=0` and `leave=True` to be the default settings, so you won't need to specify them each time, like this:
from tqdm import tqdm
from functools import partial
tqdm = partial(tqdm, position=0, leave=True) # this line does the magic
# for loop
for i in tqdm(range(10)):
# Some code
# list comprehension
nums = [for i in tqdm(range(10))]