feat(templating): add ${VAR} template variable substitution for YAML …#21
Merged
rafa-guedes merged 3 commits intomainfrom Feb 17, 2026
Merged
feat(templating): add ${VAR} template variable substitution for YAML …#21rafa-guedes merged 3 commits intomainfrom
rafa-guedes merged 3 commits intomainfrom
Conversation
…configs
Add template variable substitution system supporting environment variables,
defaults, and datetime processing in YAML configuration files.
Features:
- ${VAR} syntax for environment variable substitution
- ${VAR:-default} for default values
- Type conversion (int, float, bool) for exact-match expressions
- Datetime filters: as_datetime, strftime, shift
- Filter chaining: ${CYCLE|as_datetime|shift:-1d|strftime:%Y%m%d}
- Recursive processing of dict/list/str structures
Implementation:
- New module: src/rompy/templating.py (390 lines)
- Integrated into cli.py load_config() between YAML parse and Pydantic validation
- Zero external dependencies
- Comprehensive tests (450+ lines, 60+ test cases)
- Full documentation with examples
This enables dynamic config generation for operational workflows where
file paths, dates, and environment-specific values need to be templated.
Separate from existing cookiecutter ({{...}}) which renders model control
files. This handles config-level substitution before Pydantic validation.
…d type handling Fix 3 failing tests in test_templating.py: - test_parse_invalid_format: Update regex to match 'Cannot parse.*datetime' - test_shift_invalid_unit: Update expected error from 'Unknown time unit' to 'Invalid shift format' - test_filter_chain_in_exact_match: Skip type conversion when filters are applied - This prevents strftime output like '20221231' from being auto-converted to int
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…configs
Add template variable substitution system supporting environment variables, defaults, and datetime processing in YAML configuration files.
Features:
Implementation:
This enables dynamic config generation for operational workflows where file paths, dates, and environment-specific values need to be templated.
Separate from existing cookiecutter ({{...}}) which renders model control files. This handles config-level substitution before Pydantic validation.