fix: revise some r-strings in SPM's EstimateContrast

By removing some space concatenation of strings, some of them were
r-strings and the concatenated one contained ``\n``, effectively
escaping the special return-carriage.

Instead of concatenating strings, the interface now accumulates the
lines in a list that is joined in the end.

Author: oesteban

nipype/interfaces/spm/model.py

@@ -437,8 +437,7 @@ class EstimateContrast(SPMCommand):
     _jobname = "con"
 
     def _make_matlab_command(self, _):
-        """validates spm options and generates job structure
-        """
+        """Validate spm options and generate job structure."""
         contrasts = []
         cname = []
         for i, cont in enumerate(self.inputs.contrasts):
@@ -457,80 +456,80 @@ def _make_matlab_command(self, _):
                 contrasts[i].weights = cont[3]
             if len(cont) >= 5:
                 contrasts[i].sessions = cont[4]
-        script = "% generated by nipype.interfaces.spm\n"
-        script += "spm_defaults;\n"
-        script += "jobs{1}.stats{1}.con.spmmat  = {'%s'};\n" % self.inputs.spm_mat_file
-        script += "load(jobs{1}.stats{1}.con.spmmat{:});\n"
-        script += "SPM.swd = '%s';\n" % os.getcwd()
-        script += "save(jobs{1}.stats{1}.con.spmmat{:},'SPM');\n"
-        script += "names = SPM.xX.name;\n"
+        script = ["""\
+% generated by nipype.interfaces.spm
+spm_defaults;
+jobs{1}.stats{1}.con.spmmat  = {'%s'};
+load(jobs{1}.stats{1}.con.spmmat{:});
+SPM.swd = '%s';
+save(jobs{1}.stats{1}.con.spmmat{:},'SPM');
+names = SPM.xX.name;
+""" % (self.inputs.spm_mat_file, os.getcwd())]
         # get names for columns
         if isdefined(self.inputs.group_contrast) and self.inputs.group_contrast:
-            script += "condnames=names;\n"
+            script += ["condnames=names;"]
         else:
             if self.inputs.use_derivs:
-                script += r"pat = 'Sn\([0-9]*\) (.*)';\n"
+                script += [r"pat = 'Sn\([0-9]*\) (.*)';"]
             else:
-                script += (
-                    r"pat = 'Sn\([0-9]*\) (.*)\*bf\(1\)|Sn\([0-9]*\) "
-                    r".*\*bf\([2-9]\)|Sn\([0-9]*\) (.*)';"
-                    "\n"
-                )
-            script += "t = regexp(names,pat,'tokens');\n"
+                script += [r"""\
+pat = 'Sn\([0-9]*\) (.*)\*bf\(1\)|Sn\([0-9]*\) .*\*bf\([2-9]\)|Sn\([0-9]*\) (.*)';"""]
+
+            script += ["t = regexp(names,pat,'tokens');"]
             # get sessidx for columns
-            script += r"pat1 = 'Sn\(([0-9].*)\)\s.*';\n"
-            script += "t1 = regexp(names,pat1,'tokens');\n"
-            script += (
-                "for i0=1:numel(t),condnames{i0}='';condsess(i0)=0;if "
-                "~isempty(t{i0}{1}),condnames{i0} = t{i0}{1}{1};"
-                "condsess(i0)=str2num(t1{i0}{1}{1});end;end;\n"
-            )
+            script += [r"pat1 = 'Sn\(([0-9].*)\)\s.*';"]
+            script += ["t1 = regexp(names,pat1,'tokens');"]
+            script += ["""\
+for i0=1:numel(t)
+  condnames{i0}='';
+  condsess(i0)=0;
+  if ~isempty(t{i0}{1})
+    condnames{i0} = t{i0}{1}{1};
+    condsess(i0)=str2num(t1{i0}{1}{1});
+  end;
+end;
+"""]
+
         # BUILD CONTRAST SESSION STRUCTURE
         for i, contrast in enumerate(contrasts):
             if contrast.stat == "T":
-                script += "consess{%d}.tcon.name   = '%s';\n" % (i + 1, contrast.name)
-                script += "consess{%d}.tcon.convec = zeros(1,numel(names));\n" % (i + 1)
+                script += ["consess{%d}.tcon.name   = '%s';" % (i + 1, contrast.name)]
+                script += ["consess{%d}.tcon.convec = zeros(1,numel(names));" % (i + 1)]
                 for c0, cond in enumerate(contrast.conditions):
-                    script += "idx = strmatch('%s',condnames,'exact');\n" % (cond)
-                    script += (
-                        "if isempty(idx), throw(MException("
-                        "'CondName:Chk', sprintf('Condition %%s not "
-                        "found in design','%s'))); end;\n"
-                    ) % cond
+                    script += ["idx = strmatch('%s',condnames,'exact');" % cond]
+                    script += ["""\
+if isempty(idx)
+  throw(MException('CondName:Chk', sprintf('Condition %%s not found in design','%s')));
+end;
+""" % cond]
                     if contrast.sessions:
                         for sno, sw in enumerate(contrast.sessions):
-                            script += "sidx = find(condsess(idx)==%d);\n" % (sno + 1)
-                            script += "consess{%d}.tcon.convec(idx(sidx)) = %f;\n" % (
+                            script += ["sidx = find(condsess(idx)==%d);" % (sno + 1)]
+                            script += ["consess{%d}.tcon.convec(idx(sidx)) = %f;" % (
                                 i + 1,
                                 sw * contrast.weights[c0],
-                            )
+                            )]
                     else:
-                        script += "consess{%d}.tcon.convec(idx) = %f;\n" % (
+                        script += ["consess{%d}.tcon.convec(idx) = %f;" % (
                             i + 1,
                             contrast.weights[c0],
-                        )
+                        )]
         for i, contrast in enumerate(contrasts):
             if contrast.stat == "F":
-                script += "consess{%d}.fcon.name   =  '%s';\n" % (i + 1, contrast.name)
+                script += ["consess{%d}.fcon.name   =  '%s';" % (i + 1, contrast.name)]
                 for cl0, fcont in enumerate(contrast.conditions):
-                    try:
-                        tidx = cname.index(fcont[0])
-                    except:
-                        Exception(
-                            "Contrast Estimate: could not get index of"
-                            " T contrast. probably not defined prior "
-                            "to the F contrasts"
-                        )
-                    script += (
-                        "consess{%d}.fcon.convec{%d} = consess{%d}.tcon.convec;\n"
-                    ) % (i + 1, cl0 + 1, tidx + 1)
-        script += "jobs{1}.stats{1}.con.consess = consess;\n"
-        script += (
-            "if strcmp(spm('ver'),'SPM8'), spm_jobman('initcfg');"
-            "jobs=spm_jobman('spm5tospm8',{jobs});end\n"
-        )
-        script += "spm_jobman('run',jobs);"
-        return script
+                    tidx = cname.index(fcont[0])
+                    script += ["consess{%d}.fcon.convec{%d} = consess{%d}.tcon.convec;" %
+                               (i + 1, cl0 + 1, tidx + 1)]
+        script += ["jobs{1}.stats{1}.con.consess = consess;"]
+        script += ["""\
+if strcmp(spm('ver'),'SPM8')
+  spm_jobman('initcfg');
+  jobs=spm_jobman('spm5tospm8',{jobs});
+end;
+"""]
+        script += ["spm_jobman('run',jobs);"]
+        return "\n".join(script)
 
     def _list_outputs(self):
         import scipy.io as sio