Remove printed messages, remove MPI when nprocs=1

run_epoch.py

@@ -104,9 +104,8 @@ def singularity_cmd(
     container: str, output: Path, dims: int, photons: bool, nprocs: int
 ) -> str:
     """Constructs the command to run Epoch via a Singularity container."""
-    return dedent(
+    cmd = dedent(
         f"""\
-        mpirun -n {nprocs}
         singularity exec
         --bind {output.resolve()}:/output
         {container}
@@ -116,6 +115,7 @@ def singularity_cmd(
         {'--photons' if photons else ''}
         """
     ).replace("\n", " ")
+    return f"mpirun -n {nprocs} " + cmd if nprocs != 1 else cmd
 
 
 def main() -> None:

src/epoch_containers/run_epoch.py

@@ -103,12 +103,8 @@ def run_epoch(
 
     if not output.is_dir():
         raise NotADirectoryError(str(output))
-    full_path = output.resolve()
-    print(f"Running on the directory {full_path}, containing:")
-    for f in full_path.iterdir():
-        print(f"- {f.name}")
 
-    subprocess.run([exe], input=str(full_path).encode("utf-8"))
+    subprocess.run([exe], input=str(output.resolve()).encode("utf-8"))
 
 
 def main() -> None: