title: Where is this TypeError coming from? (Using actin for stellar activity indices) TypeError: expected str, bytes or os.PathLike object, not bool
body: <p>I'm using a package that can be found here: <a href="https://github.com/gomesdasilva/ACTIN" rel="nofollow noreferrer">https://github.com/gomesdasilva/ACTIN</a> to find activity indices for a binary system. Intially, I've run the code on a standalone test file on spyder and it all seems to work fine:</p>
  <pre><code>import actin.actin as actin
  
  actin.actin(&quot;C://Users//Rp199/Desktop//J0608_59_harps_2018//HARPS.2019-08-22T08_37_32.360_s1d_A.fits&quot;,
              calc_index=['I_CaII'], rv_in=None,
              config_file=&quot;C:\\Users\\Rp199\\anaconda3\\Lib\\site-packages\\actin\config_lines.txt&quot;,
              save_output=True, ln_plts=False, obj_name=False, targ_list='J0608-59',
              del_out=False, frac=True, test=False, save_plots=False)
  
  EXECUTING ACTIN_FILE
  --------------------
  Executing: check_targ
  Targets = J0608-59
  Object = J0608-59
  
  LOADING DATA FROM CONFIG FILE
  -----------------------------
  CaIIK
  CaIIH
  CaIIR1
  CaIIR2
  
  READING DATA FROM FILE:
  -----------------------
  Working folder: C://Users//Rp199/Desktop//J0608_59_harps_2018\
  Reading file:   HARPS.2019-08-22T08_37_32.360_s1d_A.fits
  Telescope:  ESO-3P6
  Instrument: HARPS
  Object:     J0608-59
  *** WARNING: Could not find or open:
  *** C://Users//Rp199/Desktop//J0608_59_harps_2018\HARPS.2019-08-22T*_ccf_*_A.fits
  *** WARNING: No CCF data available.
  *** WARNING: Could not find or open:
  *** C://Users//Rp199/Desktop//J0608_59_harps_2018\HARPS.2019-08-22T*_bis_*_A.fits
  *** WARNING: No BIS data available.
  *** ERROR: No rv data available to calibrate wavelength.
  
  ---------------------------------
  Fractional pixels:  True
  Files analysed:     1
  Save output:        True
  Elapsed time:       0.0013 min
  
  </code></pre>
  <p>The output states it doesn't have the CCF and BIS files which is correct.</p>
  <p>I now try to run the code on another fits file, however, in this folder there are the BIS and CCF files and receive the output:</p>
  <pre><code>READING DATA FROM FILE:
  -----------------------
  Working folder: C://Users//Rp199//Desktop//DATA_NEW\
  Reading file:   HARPS.2019-01-20T05_16_29.969_s1d_A.fits
  Telescope:  ESO-3P6
  Instrument: HARPS
  Object:     J0608-59
  CCF file:   HARPS.2019-01-20T05_16_29.969_ccf_G2_A.fits
  BIS file:   HARPS.2019-01-20T05_16_29.969_bis_G2_A.fits
  
  Executing check_duplicate:
  Traceback (most recent call last):
  
    File &quot;C:\Users\Rp199\Desktop\actintest.py&quot;, line 10, in &lt;module&gt;
      actin.actin(&quot;C://Users//Rp199//Desktop//DATA_NEW//HARPS.2019-01-20T05_16_29.969_s1d_A.fits&quot;,
  
    File &quot;C:\Users\Rp199\anaconda3\lib\site-packages\actin\actin.py&quot;, line 225, in actin
      output = actin_file(files_list[k][i][j],
  
    File &quot;C:\Users\Rp199\anaconda3\lib\site-packages\actin\actin.py&quot;, line 92, in actin_file
      dupl = ac_save.check_duplicate(data['obj'], data['obs_date'], data['instr'], data['file_type'], save_output)
  
    File &quot;C:\Users\Rp199\anaconda3\Lib\site-packages\actin\actin_files\ac_save.py&quot;, line 45, in check_duplicate
      pfile_name = os.path.join(out_dir, obj, file_name)
  
    File &quot;C:\Users\Rp199\anaconda3\lib\ntpath.py&quot;, line 78, in join
      path = os.fspath(path)
  
  TypeError: expected str, bytes or os.PathLike object, not bool
  </code></pre>
  <p>I'm confused as to why this error occurs, especially when testing with the standalone file without any CCF or BIS file in the same folder, there are no errors.</p>
  <p>Thanks</p>