normalize_namelists.py

normalize_namelists.py#

Normalizes style in eCLM namelist files so that diffs between runs are clean and human-readable.

What it does#

The script applies three transformations to every namelist file it finds:

Indentation — lines inside a &group … / block are re-indented to exactly two spaces. Group header (&group) and closing (/) lines are left as-is.
Quote style — string values delimited by double quotes are rewritten to use single quotes ("value" → 'value'). The value content is never modified.
Continuation alignment — continuation lines of multi-line values are indented to align with the value start on the key = value line above:
```
  hist_fincl1 = 'SOILWATER_10CM', 'H2OSOI',
                'SOILLIQ', 'SOILICE'
```

Lines outside a group (blank lines, comment blocks appended by modify_case_namelists.py, etc.) are passed through unchanged.

Files processed#

The script looks for the following files in the target directory:

File	Description
`drv_flds_in`	Driver field list
`drv_in`	Driver namelist
`lnd_in`	Land model namelist
`datm_in`	Data atmosphere namelist
`mosart_in`	River routing namelist
`{atm,cpl,esp,glc,ice,lnd,ocn,rof,wav}_modelio.nml`	Per-component I/O namelists

Files that are not present in the directory are silently skipped.

Usage#

# Normalize all namelist files in the current directory
python3 normalize_namelists.py

# Normalize files in a specific run directory
python3 normalize_namelists.py /path/to/rundir

# Preview which files would change without writing anything
python3 normalize_namelists.py --dry-run [rundir]

Options#

Option	Description
`rundir`	Path to the directory containing namelist files. Defaults to `.`
`--dry-run`	Print which files would be modified without writing any changes

Output#

For each file the script reports one of three outcomes:

lnd_in: normalized        # file was changed and written
drv_in: no changes        # file was already normalized
datm_in: would be modified  # --dry-run: file would change