From e6b57f2e6681fa600ed72db01d6dc423ad04a979 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 17:33:23 +0200
Subject: [PATCH 1/9] Add main

---
 .../CommonConstants/make_pdg_header.py        | 101 ++++++++++--------
 1 file changed, 55 insertions(+), 46 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index a94450e659acd..0f87ce803ce4f 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -23,7 +23,6 @@
 
 import ROOT  # pylint: disable=import-error
 
-name_script = os.path.basename(__file__)
 
 # Enum of PDG_t particles
 class PdgROOT(Enum):
@@ -149,6 +148,7 @@ class Pdg(Enum):
     kHyperHelium4Sigma = 1110020040
     kLambda1520_Py = 102134  # PYTHIA code different from PDG
 
+
 dbPdg = ROOT.o2.O2DatabasePDG
 
 
@@ -159,49 +159,58 @@ def mass(code):
     return dbPdg.Mass(code, success)
 
 
-def declare_mass(pdg, type="double") -> str:
+def declare_mass(pdg, val_type="double") -> str:
     """Returns a C++ declaration of a particle mass constant."""
-    return f"constexpr {type} Mass{pdg.name[1:]} = {mass(pdg.value)};\n"
-
-
-# Comment at the beginning of the output
-str_block_begin = f"""// BEGINNING OF THE GENERATED BLOCK.
-// DO NOT EDIT THIS BLOCK DIRECTLY!
-// It has been generated by the {name_script} script.
-// For modifications, edit the script and generate this block again.
-"""
-# Comment at the end of the output
-str_block_end = """// END OF THE GENERATED BLOCK
-"""
-# Start of enum declarations of additional particles
-str_enum_head = """/// \\brief Declarations of named PDG codes of particles missing in ROOT PDG_t
-/// \\note Follow kCamelCase naming convention
-/// \\link https://root.cern/doc/master/TPDGCode_8h.html
-enum Pdg {
-"""
-# End of enum declarations of additional particles
-str_enum_foot = "};\n"
-# Documentation string for mass declarations of additional particles
-str_mass_o2_head = """/// \\brief Declarations of masses for additional particles
-"""
-# Documentation string for mass declarations of PDG_t particles
-str_mass_root_head = """/// \\brief Declarations of masses for particles in ROOT PDG_t
-"""
-
-# Additional particles
-str_enum = str_enum_head
-str_mass_o2 = str_mass_o2_head
-for c in Pdg:
-    str_enum += f"  {c.name} = {c.value},\n"
-    str_mass_o2 += declare_mass(c)
-str_enum = str_enum[:-2] + "\n"  # Remove the last comma.
-str_enum += str_enum_foot
-
-# PDG_t particles
-str_mass_root = str_mass_root_head
-for d in PdgROOT:
-    str_mass_root += declare_mass(d)
-
-# Header body
-str_header = "\n".join((str_block_begin, str_enum, str_mass_o2, str_mass_root, str_block_end))
-print(str_header)
+    return f"constexpr {val_type} Mass{pdg.name[1:]} = {mass(pdg.value)};\n"
+
+
+def main():
+    """Main function"""
+
+    name_script = os.path.basename(__file__)
+
+    # Comment at the beginning of the output
+    str_block_begin = "// BEGINNING OF THE GENERATED BLOCK."
+    # Preamble with instructions
+    str_block_preamble = (
+        "// DO NOT EDIT THIS BLOCK DIRECTLY!"
+        f"\n// It has been generated by the {name_script} script."
+        "\n// For modifications, edit the script and generate this block again.\n"
+    )
+    # Comment at the end of the output
+    str_block_end = "// END OF THE GENERATED BLOCK"
+    # Start of enum declarations of additional particles
+    str_enum_head = (
+        "/// \\brief Declarations of named PDG codes of particles missing in ROOT PDG_t"
+        "\n/// \\note Follow kCamelCase naming convention"
+        "\n/// \\link https://root.cern/doc/master/TPDGCode_8h.html"
+        "\nenum Pdg {"
+    )
+    # End of enum declarations of additional particles
+    str_enum_foot = "};\n"
+    # Documentation string for mass declarations of additional particles
+    str_mass_o2_head = "/// \\brief Declarations of masses for additional particles"
+    # Documentation string for mass declarations of PDG_t particles
+    str_mass_root_head = "/// \\brief Declarations of masses for particles in ROOT PDG_t"
+
+    # Additional particles
+    str_enum = str_enum_head
+    str_mass_o2 = str_mass_o2_head
+    for c in Pdg:
+        str_enum += f"  {c.name} = {c.value},\n"
+        str_mass_o2 += declare_mass(c)
+    str_enum = str_enum[:-2] + "\n"  # Remove the last comma.
+    str_enum += str_enum_foot
+
+    # PDG_t particles
+    str_mass_root = str_mass_root_head
+    for d in PdgROOT:
+        str_mass_root += declare_mass(d)
+
+    # Header body
+    str_header = "\n".join((str_block_begin, str_block_preamble, str_enum, str_mass_o2, str_mass_root, str_block_end))
+    print(str_header)
+
+
+if __name__ == "__main__":
+    main()

From d9b80ebbbde59df04050f527324377d2e4c18958 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 18:39:08 +0200
Subject: [PATCH 2/9] Produce the whole file

---
 .../CommonConstants/make_pdg_header.py        | 85 ++++++++++++++-----
 1 file changed, 64 insertions(+), 21 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index 0f87ce803ce4f..e14a4407e8c80 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -18,6 +18,7 @@
 """
 
 import os
+import sys
 from ctypes import c_bool
 from enum import Enum
 
@@ -161,7 +162,7 @@ def mass(code):
 
 def declare_mass(pdg, val_type="double") -> str:
     """Returns a C++ declaration of a particle mass constant."""
-    return f"constexpr {val_type} Mass{pdg.name[1:]} = {mass(pdg.value)};\n"
+    return f"constexpr {val_type} Mass{pdg.name[1:]} = {mass(pdg.value)};"
 
 
 def main():
@@ -170,46 +171,88 @@ def main():
     name_script = os.path.basename(__file__)
 
     # Comment at the beginning of the output
-    str_block_begin = "// BEGINNING OF THE GENERATED BLOCK."
+    block_begin = "// BEGINNING OF THE GENERATED BLOCK."
     # Preamble with instructions
-    str_block_preamble = (
+    block_preamble = (
         "// DO NOT EDIT THIS BLOCK DIRECTLY!"
         f"\n// It has been generated by the {name_script} script."
-        "\n// For modifications, edit the script and generate this block again.\n"
+        "\n// For modifications, edit the script and generate this block again."
     )
     # Comment at the end of the output
-    str_block_end = "// END OF THE GENERATED BLOCK"
+    block_end = "// END OF THE GENERATED BLOCK"
     # Start of enum declarations of additional particles
-    str_enum_head = (
+    enum_o2_head = (
         "/// \\brief Declarations of named PDG codes of particles missing in ROOT PDG_t"
         "\n/// \\note Follow kCamelCase naming convention"
         "\n/// \\link https://root.cern/doc/master/TPDGCode_8h.html"
         "\nenum Pdg {"
     )
     # End of enum declarations of additional particles
-    str_enum_foot = "};\n"
+    enum_o2_foot = "};"
     # Documentation string for mass declarations of additional particles
-    str_mass_o2_head = "/// \\brief Declarations of masses for additional particles"
+    mass_o2_head = "/// \\brief Declarations of masses for additional particles"
     # Documentation string for mass declarations of PDG_t particles
-    str_mass_root_head = "/// \\brief Declarations of masses for particles in ROOT PDG_t"
+    mass_root_head = "/// \\brief Declarations of masses for particles in ROOT PDG_t"
+
+    # Get header content before and after the generated block.
+    path_header = "PhysicsConstants.h"
+    try:
+        with open(path_header, encoding="utf-8") as file:
+            content_old = file.readlines()
+    except OSError:
+        print(f'Failed to open file "{path_header}".')
+        sys.exit(1)
+    lines_header_before: list[str] = []
+    lines_header_after: list[str] = []
+    got_block_begin = False
+    got_block_end = False
+    for line in content_old:
+        line = line.strip()
+        if line == block_begin:
+            got_block_begin = True
+        if not got_block_begin:
+            lines_header_before.append(line)
+        if got_block_end:
+            lines_header_after.append(line)
+        if line == block_end:
+            got_block_end = True
+    if not got_block_begin:
+        raise ValueError("Did not find the beginning of the block.")
+    if not got_block_end:
+        raise ValueError("Did not find the end of the block.")
 
     # Additional particles
-    str_enum = str_enum_head
-    str_mass_o2 = str_mass_o2_head
-    for c in Pdg:
-        str_enum += f"  {c.name} = {c.value},\n"
-        str_mass_o2 += declare_mass(c)
-    str_enum = str_enum[:-2] + "\n"  # Remove the last comma.
-    str_enum += str_enum_foot
+    lines_enum_o2: list[str] = [enum_o2_head]
+    lines_mass_o2: list[str] = [mass_o2_head]
+    for pdg_o2 in Pdg:
+        lines_enum_o2.append(f"  {pdg_o2.name} = {pdg_o2.value},")
+        lines_mass_o2.append(declare_mass(pdg_o2))
+    lines_enum_o2[-1] = lines_enum_o2[-1][:-1]  # Remove the last comma.
+    lines_enum_o2.append(enum_o2_foot)
 
     # PDG_t particles
-    str_mass_root = str_mass_root_head
-    for d in PdgROOT:
-        str_mass_root += declare_mass(d)
+    lines_mass_root: list[str] = [mass_root_head]
+    for pdg_root in PdgROOT:
+        lines_mass_root.append(declare_mass(pdg_root))
 
     # Header body
-    str_header = "\n".join((str_block_begin, str_block_preamble, str_enum, str_mass_o2, str_mass_root, str_block_end))
-    print(str_header)
+    content_new = "\n".join(
+        (
+            *lines_header_before,
+            block_begin,
+            block_preamble,
+            "",
+            *lines_enum_o2,
+            "",
+            *lines_mass_o2,
+            "",
+            *lines_mass_root,
+            "",
+            block_end,
+            *lines_header_after,
+        )
+    )
+    print(content_new)
 
 
 if __name__ == "__main__":

From b57b40ddb3b53056ecd16d385f3d65a3068ccc76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 18:54:45 +0200
Subject: [PATCH 3/9] Write to the file

---
 .../include/CommonConstants/make_pdg_header.py        | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index e14a4407e8c80..651b83ecfeb08 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -196,6 +196,7 @@ def main():
 
     # Get header content before and after the generated block.
     path_header = "PhysicsConstants.h"
+    print(f"File {path_header} will be updated.")
     try:
         with open(path_header, encoding="utf-8") as file:
             content_old = file.readlines()
@@ -252,7 +253,15 @@ def main():
             *lines_header_after,
         )
     )
-    print(content_new)
+    # print(content_new)
+
+    try:
+        with open(path_header, "w", encoding="utf-8") as file:
+            file.write(content_new)
+            print(f"File {path_header} has been overwritten.")
+    except OSError:
+        print(f'Failed to write to file "{path_header}".')
+        sys.exit(1)
 
 
 if __name__ == "__main__":

From 972a01298384bb87fb23ed0dc52cbbde7c3dbfad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 19:05:31 +0200
Subject: [PATCH 4/9] Cosmetics

---
 Common/Constants/include/CommonConstants/make_pdg_header.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index 651b83ecfeb08..edb73c03e658c 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -160,14 +160,15 @@ def mass(code):
     return dbPdg.Mass(code, success)
 
 
-def declare_mass(pdg, val_type="double") -> str:
+def declare_mass(pdg, mass_type="double") -> str:
     """Returns a C++ declaration of a particle mass constant."""
-    return f"constexpr {val_type} Mass{pdg.name[1:]} = {mass(pdg.value)};"
+    return f"constexpr {mass_type} Mass{pdg.name[1:]} = {mass(pdg.value)};"
 
 
 def main():
     """Main function"""
 
+    path_header = "PhysicsConstants.h"
     name_script = os.path.basename(__file__)
 
     # Comment at the beginning of the output
@@ -195,7 +196,6 @@ def main():
     mass_root_head = "/// \\brief Declarations of masses for particles in ROOT PDG_t"
 
     # Get header content before and after the generated block.
-    path_header = "PhysicsConstants.h"
     print(f"File {path_header} will be updated.")
     try:
         with open(path_header, encoding="utf-8") as file:

From 31ef2d14a387edc2ec2a722f02bb2a82d8ef315b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 19:10:12 +0200
Subject: [PATCH 5/9] Update docstring

---
 Common/Constants/include/CommonConstants/make_pdg_header.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index edb73c03e658c..0810cd54e290b 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -12,7 +12,7 @@
 # or submit itself to any jurisdiction.
 
 """!
-@brief  Generates the body of a C++ header with PDG codes and particle masses.
+@brief  Generates and updates the body of a C++ header with PDG codes and particle masses.
 @author Vít Kučera <vit.kucera@cern.ch>, Inha University
 @date   2023-09-21
 """

From c4297afd3744208fdf8987cdec9bdb1aaa2c65fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 19:32:14 +0200
Subject: [PATCH 6/9] Write a newline at the EOF

---
 Common/Constants/include/CommonConstants/make_pdg_header.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index 0810cd54e290b..29ff442f7a5a5 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -251,6 +251,7 @@ def main():
             "",
             block_end,
             *lines_header_after,
+            "",
         )
     )
     # print(content_new)

From eb014f6121a2edbea27c7695cc966ab78402dda0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 19:39:33 +0200
Subject: [PATCH 7/9] Cosmetics

---
 Common/Constants/include/CommonConstants/make_pdg_header.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index 29ff442f7a5a5..edfe3b875bdaf 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -173,14 +173,14 @@ def main():
 
     # Comment at the beginning of the output
     block_begin = "// BEGINNING OF THE GENERATED BLOCK."
+    # Comment at the end of the output
+    block_end = "// END OF THE GENERATED BLOCK"
     # Preamble with instructions
     block_preamble = (
         "// DO NOT EDIT THIS BLOCK DIRECTLY!"
         f"\n// It has been generated by the {name_script} script."
         "\n// For modifications, edit the script and generate this block again."
     )
-    # Comment at the end of the output
-    block_end = "// END OF THE GENERATED BLOCK"
     # Start of enum declarations of additional particles
     enum_o2_head = (
         "/// \\brief Declarations of named PDG codes of particles missing in ROOT PDG_t"
@@ -256,6 +256,7 @@ def main():
     )
     # print(content_new)
 
+    # Overwrite the input file.
     try:
         with open(path_header, "w", encoding="utf-8") as file:
             file.write(content_new)

From cce313e357e59d297e83798723aaa80a27f5a7bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 19:55:56 +0200
Subject: [PATCH 8/9] Check loaded environment

---
 .../Constants/include/CommonConstants/make_pdg_header.py  | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index edfe3b875bdaf..4f0912a30ea57 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -22,7 +22,11 @@
 from ctypes import c_bool
 from enum import Enum
 
-import ROOT  # pylint: disable=import-error
+try:
+    import ROOT  # pylint: disable=import-error
+    from ROOT import o2
+except (ModuleNotFoundError, ImportError) as exc:
+    raise Exception("O2 environment is not loaded.") from exc
 
 
 # Enum of PDG_t particles
@@ -150,7 +154,7 @@ class Pdg(Enum):
     kLambda1520_Py = 102134  # PYTHIA code different from PDG
 
 
-dbPdg = ROOT.o2.O2DatabasePDG
+dbPdg = o2.O2DatabasePDG
 
 
 def mass(code):

From 869930e351f023020c9ae912122579b15202d16a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ku=C4=8Dera?=
 <26327373+vkucera@users.noreply.github.com>
Date: Fri, 24 Oct 2025 20:04:03 +0200
Subject: [PATCH 9/9] Improve exception handling

---
 .../include/CommonConstants/make_pdg_header.py  | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/Common/Constants/include/CommonConstants/make_pdg_header.py b/Common/Constants/include/CommonConstants/make_pdg_header.py
index 4f0912a30ea57..f83c44bb401db 100755
--- a/Common/Constants/include/CommonConstants/make_pdg_header.py
+++ b/Common/Constants/include/CommonConstants/make_pdg_header.py
@@ -18,7 +18,6 @@
 """
 
 import os
-import sys
 from ctypes import c_bool
 from enum import Enum
 
@@ -26,7 +25,7 @@
     import ROOT  # pylint: disable=import-error
     from ROOT import o2
 except (ModuleNotFoundError, ImportError) as exc:
-    raise Exception("O2 environment is not loaded.") from exc
+    raise OSError("O2 environment is not loaded.") from exc
 
 
 # Enum of PDG_t particles
@@ -200,13 +199,12 @@ def main():
     mass_root_head = "/// \\brief Declarations of masses for particles in ROOT PDG_t"
 
     # Get header content before and after the generated block.
-    print(f"File {path_header} will be updated.")
+    print(f'File "{path_header}" will be updated.')
     try:
         with open(path_header, encoding="utf-8") as file:
             content_old = file.readlines()
-    except OSError:
-        print(f'Failed to open file "{path_header}".')
-        sys.exit(1)
+    except OSError as exc:
+        raise OSError(f'Failed to open file "{path_header}".') from exc
     lines_header_before: list[str] = []
     lines_header_after: list[str] = []
     got_block_begin = False
@@ -264,10 +262,9 @@ def main():
     try:
         with open(path_header, "w", encoding="utf-8") as file:
             file.write(content_new)
-            print(f"File {path_header} has been overwritten.")
-    except OSError:
-        print(f'Failed to write to file "{path_header}".')
-        sys.exit(1)
+            print(f'File "{path_header}" has been overwritten.')
+    except OSError as exc:
+        raise OSError(f'Failed to write to file "{path_header}".') from exc
 
 
 if __name__ == "__main__":