# Unable to open EEGLAB file **URL:** \ **Category:** Support & Discussions\ **Tags:** eeg\ **Created:** [May 9, 2021, 3:08pm UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110 "2021-05-09T15:08:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![balandongiv](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/balandongiv/32/104_2.png) [@balandongiv](https://mne.discourse.group/u/balandongiv)\ **Post date:** [May 9, 2021, 3:08pm UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110/1 "2021-05-09T15:08:29Z")
When opening the `.set` file, using the code below ```python import mne raw = mne.io.read_raw_eeglab('s01_051017m.set') ``` the compiler return an error `IsADirectoryError: [Errno 21] Is a directory: 's01_051017m.set'` May I know how to solve this issue. The `.set` file is accessible via the following link: [https://ndownloader.figshare.com/files/14242478](https://ndownloader.figshare.com/files/14242478) - MNE-Python version: 0.21.2 - operating system: Ubuntu Appreciate for any help ---
**Author:** ![agramfort](https://avatars.discourse-cdn.com/v4/letter/a/7c8e57/32.png) [@agramfort](https://mne.discourse.group/u/agramfort)\ **Post date:** [May 9, 2021, 4:03pm UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110/2 "2021-05-09T16:03:26Z")
you passed the folder name and not the file to the read\_raw\_eeglab I tested and it works fine A ---
**Author:** ![balandongiv](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/balandongiv/32/104_2.png) [@balandongiv](https://mne.discourse.group/u/balandongiv)\ **Post date:** [May 10, 2021, 1:01am UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110/3 "2021-05-10T01:01:48Z")
Hi @agramfort , thanks for the clarification. I changed the following and now it works. ```python raw = mne.io.read_raw_eeglab('s01_051017m.set/s01_051017m.set') print(raw.annotations) ``` outputted: > Reading s01\_051017m.set/s01\_051017m.fdt > \ But within the folder `s01_051017m.set`, there are two files, `.fdt` and `.set` > s01\_051017m.set > -s01\_051017m.fdt > -s01\_051017m I am curios on how to open the `.fdt` file, or does the above amended code open the `.fdt` simultaneously? I read the documentation on `read_raw_eeglab`, and it mentioned > **input\_fname** [`str`](https://docs.python.org/3/library/stdtypes.html#str) > > Path to the .set file. If the data is stored in a separate .fdt file, it is expected to be in the same folder as the .set file However, I’m not so clear whether `.fdt` is open simultaneously. I assume, the `.fdt` contained the time series signal. Sorry, this is my first time work with `.set` file. ---
**Author:** ![balandongiv](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/balandongiv/32/104_2.png) [@balandongiv](https://mne.discourse.group/u/balandongiv)\ **Post date:** [May 10, 2021, 2:26am UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110/4 "2021-05-10T02:26:54Z")
Based on the discussion. > > > I was wondering if you have any tools for reading eeglab \`.set\` files (along wit…h \`.fdt\`) and converting to mne-python representation? > It would have seemed easy to do if not for the fact that sometimes (always?) \`scipy.io.loadmat\` fails in reading eeglab \`.set\` files (eeglab \`.set\` files are just \`.mat\` files). See my issue on \`scipy\` repo \[here\](https://github.com/scipy/scipy/issues/5516). > > > EEGLAB files are MATLAB files ... albeit with a \`.set\` extension instead of the …usual \`.mat\`. The EEGLAB files can contain the EEG data in a matlab struct field called \`data\`. However, this \`data\` field can alternatively contain a link to an accompanying (separate) \`.fdt\` (=FloatDaTa) file. > > Currently MNE-BIDS only allows the standalone \`.set\` files and thorws an error when an \`.set\`+\`.fdt\` combination is used. This should be fixed, see: > > https://github.com/mne-tools/mne-bids/blob/7403fc56b33bfe9b61e2cd7ee214ab9ad24312b0/mne\_bids/utils.py#L497-L505 > Fdt is not matlab file. It’s a companion file to a .set file that is actually a .mat file Hence, ```python import mne raw = mne.io.read_raw_eeglab('s01_051017m.set/s01_051017m.set') raw.plot(start=5, duration=5) ``` will produce the following graph ![Snap 2021-05-10 at 10.25.32](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/28368c55b59801bb7e1c3f4db92a8888d9c73e7a.png) This confirmed that, the `read_raw_eeglab` load the `.fdt` simultaneously. ---
**Author:** ![cbrnr](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/cbrnr/32/1409_2.png) [@cbrnr](https://mne.discourse.group/u/cbrnr)\ **Post date:** [May 10, 2021, 8:50am UTC](https://mne.discourse.group/t/unable-to-open-eeglab-file/3110/5 "2021-05-10T08:50:58Z")
Yes, you always pass the `.set` file, and MNE will auto-detect if there is an additional `.fdt` file.