diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index e6e23de..dc1a8dc 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -37,11 +37,17 @@ repos:
     - flake8-debugger
     - flake8-isort
     - flake8-string-format
-- repo: https://github.com/psf/black
-  rev: 21.7b0
+- repo: https://github.com/google/yapf
+  rev: v0.32.0
   hooks:
-  - id: black
+  - id: yapf
+    args: [-i]
+    additional_dependencies: [toml]
 - repo: https://github.com/PyCQA/isort
   rev: 5.10.1
   hooks:
   - id: isort
+- hooks:
+  - id: mbeautify
+  repo: https://github.com/AMYPAD/miutil
+  rev: v0.9.1
diff --git a/LICENCE.md b/LICENCE.md
index ee3b9f9..8019c8c 100644
--- a/LICENCE.md
+++ b/LICENCE.md
@@ -1,4 +1,4 @@
-Copyright 2020 AMYPAD
+Copyright 2020-2022 AMYPAD
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this project except in compliance with the License.
diff --git a/setup.cfg b/setup.cfg
index 83eb199..bc4d994 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -68,12 +68,24 @@ exclude=tests
 universal=1
 
 [flake8]
-max_line_length=88
-extend-ignore=E203,P1
+max_line_length=99
+extend-ignore=P1,E261
 exclude=.git,__pycache__,build,dist,.eggs
 
+[yapf]
+spaces_before_comment=15, 20
+arithmetic_precedence_indication=true
+allow_split_before_dict_value=false
+coalesce_brackets=True
+column_limit=99
+each_dict_entry_on_separate_line=False
+space_between_ending_comma_and_closing_bracket=False
+split_before_named_assigns=False
+split_before_closing_bracket=False
+
 [isort]
 profile=black
+line_length=99
 known_first_party=spm12,tests
 
 [tool:pytest]
diff --git a/spm12/__init__.py b/spm12/__init__.py
index 2755ed5..5a285ad 100644
--- a/spm12/__init__.py
+++ b/spm12/__init__.py
@@ -1,5 +1,5 @@
-from .regseg import *  # NOQA
-from .utils import *  # NOQA
+from .regseg import *  # yapf: disable # NOQA
+from .utils import *  # yapf: disable # NOQA
 
 # version detector. Precedence: installed dist, git, 'UNKNOWN'
 try:
diff --git a/spm12/__main__.py b/spm12/__main__.py
index daf9fc5..178f37e 100755
--- a/spm12/__main__.py
+++ b/spm12/__main__.py
@@ -3,5 +3,5 @@
 
 from .cli import main
 
-if __name__ == "__main__":  # pragma: no cover
+if __name__ == "__main__": # pragma: no cover
     sys.exit(main(sys.argv[1:]))
diff --git a/spm12/amypad_coreg.m b/spm12/amypad_coreg.m
index ae8199d..9eacfbf 100644
--- a/spm12/amypad_coreg.m
+++ b/spm12/amypad_coreg.m
@@ -1,28 +1,28 @@
 function [M, x] = amypad_coreg(imref, imflo, costfun, sep, tol, fwhm, params, graphics, visual)
-    if visual>0
-        Fgraph = spm_figure('GetWin','Graphics');
-        Finter = spm_figure('GetWin','Interactive');
-    end
+if visual > 0
+    Fgraph = spm_figure('GetWin', 'Graphics');
+    Finter = spm_figure('GetWin', 'Interactive');
+end
 
-    cflags.cost_fun = costfun;
-    cflags.sep = sep;
-    cflags.tol = tol;
-    cflags.fwhm = fwhm;
-    cflags.params = params;
-    cflags.graphics = graphics;
+cflags.cost_fun = costfun;
+cflags.sep = sep;
+cflags.tol = tol;
+cflags.fwhm = fwhm;
+cflags.params = params;
+cflags.graphics = graphics;
 
-    VG = strcat(imref,',1');
-    VF = strcat(imflo,',1');
+VG = strcat(imref, ',1');
+VF = strcat(imflo, ',1');
 
-    %disp('Matlab internal reference image:'); disp(imref);
-    %disp('Matlab internal floating image:'); disp(imflo);
-    %disp(cflags);
-    %disp(tol);
+%disp('Matlab internal reference image:'); disp(imref);
+%disp('Matlab internal floating image:'); disp(imflo);
+%disp(cflags);
+%disp(tol);
 
-    spm_jobman('initcfg')
-    x = spm_coreg(VG, VF, cflags);
-    M = spm_matrix(x);
+spm_jobman('initcfg')
+x = spm_coreg(VG, VF, cflags);
+M = spm_matrix(x);
 
-    %disp('translations and rotations:'); disp(x);
-    %disp('affine matrix:'); disp(M);
+%disp('translations and rotations:'); disp(x);
+%disp('affine matrix:'); disp(M);
 end
diff --git a/spm12/amypad_coreg_modify_affine.m b/spm12/amypad_coreg_modify_affine.m
index 569f74c..be1e28f 100644
--- a/spm12/amypad_coreg_modify_affine.m
+++ b/spm12/amypad_coreg_modify_affine.m
@@ -1,7 +1,7 @@
 function out = amypad_coreg_modify_affine(imflo, M)
-    VF = strcat(imflo,',1');
-    MM = zeros(4,4);
-    MM(:,:) = spm_get_space(VF);
-    spm_get_space(VF, M\MM(:,:));
-    out = 0;
+VF = strcat(imflo, ',1');
+MM = zeros(4, 4);
+MM(:, :) = spm_get_space(VF);
+spm_get_space(VF, M \ MM(:, :));
+out = 0;
 end
diff --git a/spm12/amypad_normw.m b/spm12/amypad_normw.m
index f7570a5..d80755d 100644
--- a/spm12/amypad_normw.m
+++ b/spm12/amypad_normw.m
@@ -1,10 +1,10 @@
 function out = amypad_normw(def_file, flist4norm)
-    job.subj.def = {def_file};
-    job.subj.resample = flist4norm;
-    job.woptions.bb = [NaN, NaN, NaN; NaN, NaN, NaN];
-    job.woptions.vox = [2, 2, 2];
-    job.woptions.interp = 4;
-    job.woptions.prefix = 'w';
-    spm_run_norm(job);
-    out=0;
+job.subj.def = {def_file};
+job.subj.resample = flist4norm;
+job.woptions.bb = [NaN, NaN, NaN; NaN, NaN, NaN];
+job.woptions.vox = [2, 2, 2];
+job.woptions.interp = 4;
+job.woptions.prefix = 'w';
+spm_run_norm(job);
+out = 0;
 end
diff --git a/spm12/amypad_resample.m b/spm12/amypad_resample.m
index c942f85..921110f 100644
--- a/spm12/amypad_resample.m
+++ b/spm12/amypad_resample.m
@@ -1,23 +1,23 @@
 function out = amypad_resample(imref, imflo, M, f_mask, f_mean, f_interp, f_which, f_prefix)
-    %-Reslicing parameters
-    rflags.mask = f_mask;
-    rflags.mean = f_mean;
-    rflags.interp = f_interp;
-    rflags.which = f_which;
-    rflags.wrap = [0 0 0];
-    rflags.prefix = f_prefix;
+%-Reslicing parameters
+rflags.mask = f_mask;
+rflags.mean = f_mean;
+rflags.interp = f_interp;
+rflags.which = f_which;
+rflags.wrap = [0, 0, 0];
+rflags.prefix = f_prefix;
 
-    VG = strcat(imref,',1');
-    VF = strcat(imflo,',1');
+VG = strcat(imref, ',1');
+VF = strcat(imflo, ',1');
 
-    % disp('Matlab internal reference image:'); disp(imref);
-    % disp('Matlab internal floating image:'); disp(imflo);
-    % disp(rflags)
+% disp('Matlab internal reference image:'); disp(imref);
+% disp('Matlab internal floating image:'); disp(imflo);
+% disp(rflags)
 
-    MM = zeros(4,4);
-    MM(:, :) = spm_get_space(VF);
-    spm_get_space(VF, M\MM(:, :));
-    P = {VG; VF};
-    spm_reslice(P, rflags);
-    out = 0;
+MM = zeros(4, 4);
+MM(:, :) = spm_get_space(VF);
+spm_get_space(VF, M \ MM(:, :));
+P = {VG; VF};
+spm_reslice(P, rflags);
+out = 0;
 end
diff --git a/spm12/amypad_seg.m b/spm12/amypad_seg.m
index 42bf585..9f4f4df 100644
--- a/spm12/amypad_seg.m
+++ b/spm12/amypad_seg.m
@@ -1,46 +1,46 @@
-function [param,invdef,fordef] = amypad_seg(f_mri, spm_path, nat_gm, nat_wm, nat_csf, store_fwd, store_inv, visual)
-    job.channel.vols = {strcat(f_mri,',1')};
-    job.channel.biasreg = 0.001;
-    job.channel.biasfwhm = 60;
-    job.channel.write = [0, 0];
-    job.tissue(1).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,1']};
-    job.tissue(1).ngaus = 1;
-    job.tissue(1).native = [nat_gm, 0];
-    job.tissue(1).warped = [0, 0];
-    job.tissue(2).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,2']};
-    job.tissue(2).ngaus = 1;
-    job.tissue(2).native = [nat_wm, 0];
-    job.tissue(2).warped = [0, 0];
-    job.tissue(3).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,3']};
-    job.tissue(3).ngaus = 2;
-    job.tissue(3).native = [nat_csf, 0];
-    job.tissue(3).warped = [0, 0];
-    job.tissue(4).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,4']};
-    job.tissue(4).ngaus = 3;
-    job.tissue(4).native = [0, 0];
-    job.tissue(4).warped = [0, 0];
-    job.tissue(5).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,5']};
-    job.tissue(5).ngaus = 4;
-    job.tissue(5).native = [0, 0];
-    job.tissue(5).warped = [0, 0];
-    job.tissue(6).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,6']};
-    job.tissue(6).ngaus = 2;
-    job.tissue(6).native = [0, 0];
-    job.tissue(6).warped = [0, 0];
-    job.warp.mrf = 1;
-    job.warp.cleanup = 1;
-    job.warp.reg = [0, 0.001, 0.5, 0.05, 0.2];
-    job.warp.affreg = 'mni';
-    job.warp.fwhm = 0;
-    job.warp.samp = 3;
-    job.warp.write = [store_fwd, store_inv];
-    if visual>0
-        Finter = spm_figure('GetWin','Interactive');
-    end
-    spm_jobman('initcfg');
-    segout = spm_preproc_run(job);
-    param  = segout.param{1};
-    invdef = segout.invdef{1};
-    fordef = segout.fordef{1};
-    %disp(segout);
+function [param, invdef, fordef] = amypad_seg(f_mri, spm_path, nat_gm, nat_wm, nat_csf, store_fwd, store_inv, visual)
+job.channel.vols = {strcat(f_mri, ',1')};
+job.channel.biasreg = 0.001;
+job.channel.biasfwhm = 60;
+job.channel.write = [0, 0];
+job.tissue(1).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,1']};
+job.tissue(1).ngaus = 1;
+job.tissue(1).native = [nat_gm, 0];
+job.tissue(1).warped = [0, 0];
+job.tissue(2).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,2']};
+job.tissue(2).ngaus = 1;
+job.tissue(2).native = [nat_wm, 0];
+job.tissue(2).warped = [0, 0];
+job.tissue(3).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,3']};
+job.tissue(3).ngaus = 2;
+job.tissue(3).native = [nat_csf, 0];
+job.tissue(3).warped = [0, 0];
+job.tissue(4).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,4']};
+job.tissue(4).ngaus = 3;
+job.tissue(4).native = [0, 0];
+job.tissue(4).warped = [0, 0];
+job.tissue(5).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,5']};
+job.tissue(5).ngaus = 4;
+job.tissue(5).native = [0, 0];
+job.tissue(5).warped = [0, 0];
+job.tissue(6).tpm = {[spm_path, filesep, 'tpm', filesep, 'TPM.nii,6']};
+job.tissue(6).ngaus = 2;
+job.tissue(6).native = [0, 0];
+job.tissue(6).warped = [0, 0];
+job.warp.mrf = 1;
+job.warp.cleanup = 1;
+job.warp.reg = [0, 0.001, 0.5, 0.05, 0.2];
+job.warp.affreg = 'mni';
+job.warp.fwhm = 0;
+job.warp.samp = 3;
+job.warp.write = [store_fwd, store_inv];
+if visual > 0
+    Finter = spm_figure('GetWin', 'Interactive');
+end
+spm_jobman('initcfg');
+segout = spm_preproc_run(job);
+param = segout.param{1};
+invdef = segout.invdef{1};
+fordef = segout.fordef{1};
+%disp(segout);
 end
diff --git a/spm12/cli.py b/spm12/cli.py
index 195fab4..c7bcc77 100644
--- a/spm12/cli.py
+++ b/spm12/cli.py
@@ -19,9 +19,7 @@
 
 
 def main(argv=None):
-    logging.basicConfig(
-        level=logging.DEBUG, format="%(levelname)s:%(funcName)s:%(message)s"
-    )
+    logging.basicConfig(level=logging.DEBUG, format="%(levelname)s:%(funcName)s:%(message)s")
     args = argopt(__doc__).parse_args(argv)
     log.info(args)
     if isinstance(args.command, str):
diff --git a/spm12/regseg.py b/spm12/regseg.py
index 5d5983b..3f9453e 100644
--- a/spm12/regseg.py
+++ b/spm12/regseg.py
@@ -33,7 +33,7 @@ def glob_match(pttrn, pth):
 
 
 def fwhm2sig(fwhm, voxsize=2.0):
-    return fwhm / (voxsize * (8 * np.log(2)) ** 0.5)
+    return fwhm / (voxsize * (8 * np.log(2))**0.5)
 
 
 def smoothim(fim, fwhm=4, fout=""):
@@ -41,14 +41,11 @@ def smoothim(fim, fwhm=4, fout=""):
     Smooth image using Gaussian filter with FWHM given as an option.
     """
     imd = nii.getnii(fim, output="all")
-    imsmo = ndi.filters.gaussian_filter(
-        imd["im"], fwhm2sig(fwhm, voxsize=imd["voxsize"]), mode="constant"
-    )
+    imsmo = ndi.filters.gaussian_filter(imd["im"], fwhm2sig(fwhm, voxsize=imd["voxsize"]),
+                                        mode="constant")
     if not fout:
         f = nii.file_parts(fim)
-        fout = os.path.join(
-            f[0], "{}_smo{}{}".format(f[1], str(fwhm).replace(".", "-"), f[2])
-        )
+        fout = os.path.join(f[0], "{}_smo{}{}".format(f[1], str(fwhm).replace(".", "-"), f[2]))
     nii.array2nii(
         imsmo,
         imd["affine"],
@@ -95,24 +92,15 @@ def coreg_spm(
         image according to the rigid body transformation.
     """
     out = {}  # output dictionary
+
     sep = sep or [4, 2]
     tol = tol or [
-        0.0200,
-        0.0200,
-        0.0200,
-        0.0010,
-        0.0010,
-        0.0010,
-        0.0100,
-        0.0100,
-        0.0100,
-        0.0010,
-        0.0010,
-        0.0010,
-    ]
+        0.0200, 0.0200, 0.0200, 0.0010, 0.0010, 0.0010, 0.0100, 0.0100, 0.0100, 0.0010, 0.0010,
+        0.0010]
     fwhm = fwhm or [7, 7]
     params = params or [0, 0, 0, 0, 0, 0]
-    eng = ensure_spm(matlab_eng_name)  # get_matlab
+
+    eng = ensure_spm(matlab_eng_name) # get_matlab
 
     if not outpath and fname_aff and "/" in fname_aff:
         opth = os.path.dirname(fname_aff) or os.path.dirname(imflo)
@@ -135,12 +123,7 @@ def coreg_spm(
         # delete the previous version (non-smoothed)
         os.remove(imrefu)
         imrefu = smodct["fim"]
-
-        log.info(
-            "smoothed the reference image with FWHM={} and saved to\n{}".format(
-                fwhm_ref, imrefu
-            )
-        )
+        log.info("smoothed the reference image with FWHM=%r and saved to\n%r", fwhm_ref, imrefu)
 
     # floating
     if hasext(imflo, "gz"):
@@ -158,14 +141,8 @@ def coreg_spm(
         else:
             # save the uncompressed and unsmoothed version
             imflou_ = imflou
-
         imflou = smodct["fim"]
-
-        log.info(
-            "smoothed the floating image with FWHM={} and saved to\n{}".format(
-                fwhm_ref, imrefu
-            )
-        )
+        log.info("smoothed the floating image with FWHM=%r and saved to\n%r", fwhm_ref, imrefu)
 
     # run the MATLAB SPM registration
     import matlab as ml
@@ -257,16 +234,13 @@ def resample_spm(
     del_out_uncmpr=False,
 ):
     log.debug(
-        dedent(
-            """\
+        dedent("""\
         ======================================================================
-         S P M  inputs:
-         > ref:' {}
-         > flo:' {}
-        ======================================================================"""
-        ).format(imref, imflo)
-    )
-    eng = ensure_spm(matlab_eng_name)  # get_matlab
+        SPM inputs:
+        > ref: %r
+        > flo: %r
+        ======================================================================"""), imref, imflo)
+    eng = ensure_spm(matlab_eng_name) # get_matlab
 
     if not outpath and fimout:
         opth = os.path.dirname(fimout) or os.path.dirname(imflo)
@@ -299,9 +273,7 @@ def resample_spm(
             M = np.load(M)
             log.info("matrix M given in the form of NumPy file")
         else:
-            raise IOError(
-                errno.ENOENT, M, "Unrecognised file extension for the affine."
-            )
+            raise IOError(errno.ENOENT, M, "Unrecognised file extension for the affine.")
     elif isinstance(M, (np.ndarray, np.generic)):
         log.info("matrix M given in the form of Numpy array")
     else:
@@ -310,9 +282,7 @@ def resample_spm(
     # run the Matlab SPM resampling
     import matlab as ml
 
-    eng.amypad_resample(
-        imrefu, imflou, ml.double(M.tolist()), mask, mean, intrp, which, prefix
-    )
+    eng.amypad_resample(imrefu, imflou, ml.double(M.tolist()), mask, mean, intrp, which, prefix)
 
     # -compress the output
     split = os.path.split(imflou)
@@ -345,11 +315,7 @@ def resample_spm(
 
     if fwhm > 0:
         smodct = smoothim(fout, fwhm)
-        log.info(
-            "smoothed the resampled image with FWHM={} and saved to\n{}".format(
-                fwhm, smodct["fim"]
-            )
-        )
+        log.info("smoothed the resampled image with FWHM=%r and saved to\n%r", fwhm, smodct["fim"])
 
     return fout
 
@@ -379,11 +345,13 @@ def seg_spm(
       visual: shows the Matlab window progress
     """
     out = {}  # output dictionary
+
     # get Matlab engine or use the provided one
     eng = ensure_spm(matlab_eng_name)
     if not spm_path:
         spm_path = spm_dir()
-    # run SPM normalisation/segmentation
+
+        # run SPM normalisation/segmentation
     param, invdef, fordef = eng.amypad_seg(
         f_mri,
         str(spm_path),
@@ -400,6 +368,7 @@ def seg_spm(
         out["param"] = move_files(param, outpath)
         out["invdef"] = move_files(invdef, outpath)
         out["fordef"] = move_files(fordef, outpath)
+
         # go through tissue types and move them to the output folder
         for c in glob_match(r"c\d*", os.path.dirname(param)):
             nm = os.path.basename(c)[:2]
@@ -424,19 +393,17 @@ def normw_spm(f_def, files4norm, matlab_eng_name="", outpath=None):
       matlab_eng_name: name of the Python engine for Matlab.
       outpath: output folder path for the normalisation files
     """
-    eng = ensure_spm(matlab_eng_name)  # get_matlab
+    eng = ensure_spm(matlab_eng_name) # get_matlab
     eng.amypad_normw(f_def, files4norm)
-    out = []  # output list
+    out = []                          # output list
+
     if outpath is not None:
         create_dir(outpath)
         for f in files4norm:
-            fpth = f.split(",")[0]
+            fpth = f.rsplit(",", 1)[0]
             out.append(
-                move_files(
-                    os.path.join(os.path.dirname(fpth), "w" + os.path.basename(fpth)),
-                    outpath,
-                )
-            )
+                move_files(os.path.join(os.path.dirname(fpth), "w" + os.path.basename(fpth)),
+                           outpath))
     else:
         out.append("w" + os.path.basename(f.split(",")[0]))
     return out
diff --git a/spm12/utils.py b/spm12/utils.py
index 9e8e52e..1566e41 100644
--- a/spm12/utils.py
+++ b/spm12/utils.py
@@ -12,7 +12,7 @@
 
 try:
     from functools import lru_cache
-except ImportError:  # fix py2.7
+except ImportError: # fix py2.7
     from backports.functools_lru_cache import lru_cache
 
 __all__ = ["ensure_spm", "get_matlab", "spm_dir"]
@@ -48,14 +48,11 @@ def mcr_run(*cmd, cache="~/.spm12", version=12, mcr_version=713):
         return check_output((runner, mcr_root) + cmd).decode("U8").strip()
     except CalledProcessError as err:
         raise RuntimeError(
-            dedent(
-                """\
+            dedent("""\
             {}
 
             See https://en.wikibooks.org/wiki/SPM/Standalone#Trouble-shooting
-            """
-            ).format(err)
-        )
+            """).format(err))
 
 
 @lru_cache()
@@ -91,15 +88,12 @@ def ensure_spm(name=None, cache="~/.spm12", version=12):
             if not eng.exist("spm_jobman"):
                 raise RuntimeError("MATLAB could not find SPM.")
             log.info("Installed")
-        except:  # NOQA: E722,B001
+        except:                # NOQA: E722,B001
             raise ImportError(
-                dedent(
-                    """\
+                dedent("""\
                 MATLAB could not find SPM.
                 Please follow installation instructions at
                 https://en.wikibooks.org/wiki/SPM/Download
                 Make sure to add SPM to MATLAB's path using `startup.m`
-                """
-                )
-            )
+                """))
     return eng
diff --git a/tests/__main__.py b/tests/__main__.py
index b4ee5a5..87009cf 100644
--- a/tests/__main__.py
+++ b/tests/__main__.py
@@ -6,9 +6,7 @@
 from .conftest import HOME
 
 log = logging.getLogger(__name__)
-DATA_URL = (
-    "https://zenodo.org/record/3877529/files/amyloidPET_FBP_TP0_extra.zip?download=1"
-)
+DATA_URL = ("https://zenodo.org/record/3877529/files/amyloidPET_FBP_TP0_extra.zip?download=1")
 
 
 def main():
diff --git a/tests/conftest.py b/tests/conftest.py
index 8206804..e82ff35 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -12,14 +12,10 @@ def folder_in():
     Ab_PET_mMR_test = HOME / "Ab_PET_mMR_test"
     if not Ab_PET_mMR_test.is_dir():
         skip(
-            dedent(
-                """\
+            dedent("""\
             Cannot find Ab_PET_mMR_test in ${DATA_ROOT:-~} (%s).
             Try running `python -m tests` to download it.
-            """
-            )
-            % HOME
-        )
+            """) % HOME)
     return Ab_PET_mMR_test
 
 
@@ -28,15 +24,11 @@ def folder_ref(folder_in):
     Ab_PET_mMR_ref = folder_in / "testing_reference" / "Ab_PET_mMR_ref"
     if not Ab_PET_mMR_ref.is_dir():
         skip(
-            dedent(
-                """\
+            dedent("""\
             Cannot find Ab_PET_mMR_ref in
             ${DATA_ROOT:-~}/testing_reference (%s/testing_reference).
             Try running `python -m tests` to download it.
-            """
-            )
-            % HOME
-        )
+            """) % HOME)
     return Ab_PET_mMR_ref
 
 
diff --git a/tests/test_regseg.py b/tests/test_regseg.py
index 002cc87..60869d1 100644
--- a/tests/test_regseg.py
+++ b/tests/test_regseg.py
@@ -6,14 +6,9 @@
 
 from spm12 import regseg
 
-MRI2PET = np.array(
-    [
-        [0.99990508, 0.00800995, 0.01121016, -0.68164088],
-        [-0.00806219, 0.99995682, 0.00462244, -1.16235105],
-        [-0.01117265, -0.00471238, 0.99992648, -1.02167229],
-        [0.0, 0.0, 0.0, 1.0],
-    ]
-)
+MRI2PET = np.array([[0.99990508, 0.00800995, 0.01121016, -0.68164088],
+                    [-0.00806219, 0.99995682, 0.00462244, -1.16235105],
+                    [-0.01117265, -0.00471238, 0.99992648, -1.02167229], [0.0, 0.0, 0.0, 1.0]])
 no_matlab_warn = mark.filterwarnings("ignore:.*collections.abc:DeprecationWarning")
 no_scipy_warn = mark.filterwarnings("ignore:numpy.ufunc size changed.*:RuntimeWarning")
 
@@ -22,28 +17,16 @@ def assert_equal_arrays(x, y, nmse_tol=0, denan=True):
     if denan:
         x, y = map(np.nan_to_num, (x, y))
     if nmse_tol:
-        if ((x - y) ** 2).mean() / (y ** 2).mean() < nmse_tol:
+        if ((x - y)**2).mean() / (y**2).mean() < nmse_tol:
             return
     elif (x == y).all():
         return
     raise ValueError(
-        dedent(
-            """\
+        dedent("""\
         Unequal arrays:x != y. min/mean/max(std):
         x: {:.3g}/{:.3g}/{:.3g}({:.3g})
         y: {:.3g}/{:.3g}/{:.3g}({:.3g})
-        """
-        ).format(
-            x.min(),
-            x.mean(),
-            x.max(),
-            x.std(),
-            y.min(),
-            y.mean(),
-            y.max(),
-            y.std(),
-        )
-    )
+        """).format(x.min(), x.mean(), x.max(), x.std(), y.min(), y.mean(), y.max(), y.std()))
 
 
 @no_scipy_warn