recover in-place usage by defaulting to version 0 and changing it back after installation

python/install.py

@@ -150,3 +150,10 @@ if tryuser:
     setup(**setup_kwargs)
   except:
     print("Installation into user site package folder failed.")
+
+# restore __version__ == 0 for in place usage
+with open(os.path.join('lammps','__init__.py'), "r+") as f:
+    content = f.read()
+    f.seek(0)
+    f.write(re.sub(vregex, lambda match: '{}{}'.format(match.group(1), 0), content))
+    f.truncate()

python/lammps/__init__.py

@@ -5,4 +5,4 @@ from .pylammps import *
 
 # automatically updated during installation
 
-__version__ = 20201224
+__version__ = 0

python/lammps/core.py

@@ -382,8 +382,9 @@ class lammps(object):
     self._available_styles = None
 
     # check if liblammps version matches the installed python module version
+    # but not for in-place usage, i.e. when the version is 0
     import lammps
-    if lammps.__version__ != self.lib.lammps_version(self.lmp):
+    if lammps.__version__ > 0 and lammps.__version__ != self.lib.lammps_version(self.lmp):
         raise(AttributeError("LAMMPS Python module installed for LAMMPS version %d, but shared library is version %d" \
                 % (lammps.__version__, self.lib.lammps_version(self.lmp))))