# type error to read sample data (MNE TUTORIAL) **URL:** \ **Category:** Support & Discussions\ **Created:** [September 21, 2022, 3:52pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610 "2022-09-21T15:52:50Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Student\_clem](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Student\_clem](https://mne.discourse.group/u/Student_clem)\ **Post date:** [September 21, 2022, 3:52pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/1 "2022-09-21T15:52:50Z")
- MNE version: 0.24.0 - operating system: Windows 10 hello, I’m new in MNE and i just wanted to try the first tutorial: import numpy as np import mne sample\_data\_folder = mne.datasets.sample.data\_path() sample\_data\_raw\_file = (sample\_data\_folder,‘MEG’,‘sample’, ‘sample\_audvis\_filt-0-40\_raw.fif’) Until this point it’s working. Then, this is the line that return an error: raw = mne.io.read\_raw\_fif(sample\_data\_raw\_file) return: TypeError Traceback (most recent call last) Input In [2], in \() 1 sample\_data\_folder = mne.datasets.sample.data\_path() 2 sample\_data\_raw\_file = (sample\_data\_folder,‘MEG’,‘sample’, 3 ‘sample\_audvis\_filt-0-40\_raw.fif’) ----\> 4 raw = mne.io.read\_raw\_fif(sample\_data\_raw\_file) File ~\anaconda3\lib\site-packages\mne\io\fiff\raw.py:473, in read\_raw\_fif(fname, allow\_maxshield, preload, on\_split\_missing, verbose) 438 @fill\_doc 439 def read\_raw\_fif(fname, allow\_maxshield=False, preload=False, 440 on\_split\_missing=‘raise’, verbose=None): 441 “”“Reader function for Raw FIF data. 442 443 Parameters (…) 471 … versionadded:: 0.9.0 472 “”” → 473 return Raw(fname=fname, allow\_maxshield=allow\_maxshield, 474 preload=preload, verbose=verbose, 475 on\_split\_missing=on\_split\_missing) File :24, in **init** (self, fname, allow\_maxshield, preload, on\_split\_missing, verbose) File ~\anaconda3\lib\site-packages\mne\io\fiff\raw.py:81, in Raw. **init** (self, fname, allow\_maxshield, preload, on\_split\_missing, verbose) 78 next\_fname = fname 79 while next\_fname is not None: 80 raw, next\_fname, buffer\_size\_sec = —\> 81 self.\_read\_raw\_file(next\_fname, allow\_maxshield, 82 preload, do\_check\_ext) 83 do\_check\_ext = False 84 raws.append(raw) File :24, in \_read\_raw\_file(self, fname, allow\_maxshield, preload, do\_check\_ext, verbose) File ~\anaconda3\lib\site-packages\mne\io\fiff\raw.py:136, in Raw.\_read\_raw\_file(self, fname, allow\_maxshield, preload, do\_check\_ext, verbose) 132 @verbose 133 def \_read\_raw\_file(self, fname, allow\_maxshield, preload, 134 do\_check\_ext=True, verbose=None): 135 “”“Read in header information from a raw file.”“” → 136 logger.info(‘Opening raw data file %s…’ % fname) 138 # Read in the whole file if preload is on and .fif.gz (saves time) 139 if not \_file\_like(fname): TypeError: not all arguments converted during string formatting I tried with others files from others tutorials but the issue is always the same. I can’t find on the web others with this same issue… someone to help a biginner? Thanks! Clem ---
**Author:** ![agramfort](https://avatars.discourse-cdn.com/v4/letter/a/7c8e57/32.png) [@agramfort](https://mne.discourse.group/u/agramfort)\ **Post date:** [September 22, 2022, 6:48am UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/2 "2022-09-22T06:48:59Z")
hi, you passed sample\_data\_raw\_file as a tuple not a string pointing to the file on disk. I would suggest you start by copy pasting the examples and tutorials. Alex ---
**Author:** ![drammock](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/drammock/32/4_2.png) [@drammock](https://mne.discourse.group/u/drammock)\ **Post date:** [September 22, 2022, 4:19pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/3 "2022-09-22T16:19:29Z")
to expand on what @agramfort said: this line > [@Student\_clem](#): > > sample\_data\_raw\_file = (sample\_data\_folder,‘MEG’,‘sample’, > ‘sample\_audvis\_filt-0-40\_raw.fif’) is incorrect, it should probably be something like ```python sample_data_raw_file = os.path.join(sample_data_folder,‘MEG’,‘sample’, ‘sample_audvis_filt-0-40_raw.fif’) ``` (the `os.path.join` was missing) ---
**Author:** ![Student\_clem](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Student\_clem](https://mne.discourse.group/u/Student_clem)\ **Post date:** [September 22, 2022, 7:06pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/4 "2022-09-22T19:06:38Z")
Ok it’s working now (juste needed to import os ). Actually it was missing on the tutorial page. Thank you! ---
**Author:** ![drammock](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/drammock/32/4_2.png) [@drammock](https://mne.discourse.group/u/drammock)\ **Post date:** [September 22, 2022, 7:10pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/5 "2022-09-22T19:10:53Z")
In fact the tutorial says ```python sample_data_raw_file = (sample_data_folder / 'MEG' / 'sample' / 'sample_audvis_filt-0-40_raw.fif') ``` which uses `/` instead of `,` in between each path element. That works because `sample_data_folder` is a `pathlib.Path` object, not a normal string. See [pathlib — Object-oriented filesystem paths — Python 3.10.7 documentation](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module) ---
**Author:** ![Student\_clem](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Student\_clem](https://mne.discourse.group/u/Student_clem)\ **Post date:** [September 23, 2022, 3:20pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/6 "2022-09-23T15:20:16Z")
Hi! Thank you for your explanations. I’m facing another issue, when I’m triying to read the dataset I have a File Not Found Error. I printed my files path to be shure that it exist but the read\_raw\_fif function seems not found it. ![image](https://global.discourse-cdn.com/free1/uploads/mne/original/2X/9/93bdaf032a9488fef4a8a7daa96d56fa3e18a21b.png) thanks in advance! ---
**Author:** ![drammock](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/drammock/32/4_2.png) [@drammock](https://mne.discourse.group/u/drammock)\ **Post date:** [September 23, 2022, 3:35pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/7 "2022-09-23T15:35:42Z")
printing the file path does not ensure that it exists. try `os.path.exists()` ---
**Author:** ![Student\_clem](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Student\_clem](https://mne.discourse.group/u/Student_clem)\ **Post date:** [September 23, 2022, 3:40pm UTC](https://mne.discourse.group/t/type-error-to-read-sample-data-mne-tutorial/5610/8 "2022-09-23T15:40:53Z")
ok I just tryed on colab and it’s working. I’m usiing Anaconda and from anaconda I work on jupyterlab and spyder. I have the same issue on jupyterlab and on spyder. So the problem should come from my environment… conda-build version : 3.22.0 python version : 3.9.12.final.0