support pydantic models

README.md

@@ -10,21 +10,21 @@ The configuration presedence are (from lowest to highest):
 
 # Config
 
-Arguments are parsed in two phases. First, it will look for the argument --config argument
-which can be used to specify an alternative location for the ini file. If not --config argument
-is given it will look for an ini file in the following locations (~/.config has presedence):
+Arguments are parsed in two phases. First, it will look for the argument `--config`
+which can be used to specify an alternative location for the ini file. If not `--config` argument
+is given it will look for an ini file in the following locations (`~/.config has presedence`):
 
-- ~/.config/<CONFIG_ID>/<CONFIG_FILE_NAME> (or directory specified by XDG_CONFIG_HOME)
-- /etc/<CONFIG_FILE_NAME>
+- `~/.config/<CONFIG_ID>/<CONFIG_FILE_NAME>` (or directory specified by `$XDG_CONFIG_HOME`)
+- `/etc/<CONFIG_FILE_NAME>`
 
-The ini file can contain a "[DEFAULT]" section that will be used for all configurations.
-In addition it can have a section that corresponds with <SECTION_NAME> that for
-specific configuration, that will over override config from DEFAULT
+The ini file can contain a `[DEFAULT]` section that will be used for all configurations.
+In addition it can have a section that corresponds with `<SECTION_NAME>` that for
+specific configuration, that will over override config from `[DEFAULT]`
 
 # Environment variables
 
 The configuration step will also look for environment variables in uppercase and
-with "-" replaced with "_". For the example below it will lookup the following environment
+with `-` replaced with `_`. For the example below it will lookup the following environment
 variables:
 
 - $NUMBER
@@ -33,7 +33,7 @@ variables:
 
 Example:
 
-```
+```python
 >>> import caep
 >>> import argparse
 >>> parser = argparse.ArgumentParser("test argparse")

caep/__init__.py

@@ -1,2 +1,3 @@
 from .config import handle_args  # noqa: F401
+from .schema import parse as parse  # noqa: F401
 from .xdg import get_cache_dir, get_config_dir  # noqa: F401

caep/schema.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+
+
+import argparse
+from typing import Dict, List, Optional, Type, TypeVar
+
+from pydantic import BaseModel
+
+import caep
+
+# Map of pydantic schema types to python types
+TYPE_MAPPING: Dict[str, type] = {
+    "string": str,
+    "integer": int,
+    "number": float,
+    "boolean": bool,
+}
+
+# Type of BaseModel Subclasses
+BaseModelType = TypeVar("BaseModelType", bound=BaseModel)
+
+
+class SchemaError(Exception):
+    pass
+
+
+class FieldError(Exception):
+    pass
+
+
+def parse(
+    model: Type[BaseModelType],
+    description: str,
+    config_id: str,
+    config_file_name: str,
+    section_name: str,
+    alias: bool = False,
+    opts: Optional[List[str]] = None,
+) -> BaseModelType:
+
+    """
+
+    TODO - document parameters
+
+    """
+
+    parser = argparse.ArgumentParser(description)
+
+    # Get all pydantic fields
+    fields = model.schema(alias).get("properties")
+
+    if not fields:
+        raise SchemaError(f"Unable to get properties from schema {model}")
+
+    # Map of all fields that are defined as arrays
+    arrays = {}
+
+    # Loop over all pydantic schema fields
+    for field, schema in fields.items():
+        field_type: type
+
+        # argparse arguments use dash instead of underscore
+        field = field.replace("_", "-")
+
+        if schema["type"] == "array":
+            array_type = TYPE_MAPPING.get(schema["items"]["type"])
+
+            if not array_type:
+                raise FieldError(
+                    f"Unsupported pydantic type for array field {field}: {schema}"
+                )
+
+            arrays[field] = (array_type, schema.get("split", " "))
+
+            # For arrays (lists), we parse as str in caep and split values by configured
+            # split value later
+            field_type = str
+        else:
+
+            if schema["type"] not in TYPE_MAPPING:
+                raise FieldError(
+                    f"Unsupported pydantic type for field {field}: {schema}"
+                )
+
+            field_type = TYPE_MAPPING[schema["type"]]
+
+        parser.add_argument(
+            f"--{field}",
+            help=schema.get("description", "No help provided"),
+            type=field_type,
+            default=schema.get("default"),
+        )
+
+    args = {}
+
+    for field, value in vars(
+        caep.config.handle_args(
+            parser, config_id, config_file_name, section_name, opts=opts
+        )
+    ).items():
+
+        if field in arrays:
+            if not value:
+                value = []
+            else:
+                value_type, split = arrays[field]
+                value = [value_type(v) for v in value.split(split)]
+
+        args[field] = value
+
+    return model(**args)

tests/data/config_testdata.ini

@@ -2,5 +2,5 @@
 number = 3
 
 [test]
-bool = True
+enabled = True
 str-arg = from ini

tests/test_config.py

@@ -10,14 +10,14 @@
 def __argparser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser("test argparse", allow_abbrev=False)
     parser.add_argument("--number", type=int, default=1)
-    parser.add_argument("--bool", action="store_true")
+    parser.add_argument("--enabled", action="store_true")
     parser.add_argument("--str-arg")
 
     return parser
 
 
 def test_argparse_only() -> None:
-    """all arguments from command line, using default for number and bool"""
+    """all arguments from command line, using default for number and enabled"""
 
     parser = __argparser()
 
@@ -29,7 +29,7 @@ def test_argparse_only() -> None:
 
     assert args.number == 1
     assert args.str_arg == "test"
-    assert not args.bool
+    assert not args.enabled
 
 
 def test_argparse_ini() -> None:
@@ -44,7 +44,7 @@ def test_argparse_ini() -> None:
 
     assert args.number == 3
     assert args.str_arg == "from ini"
-    assert args.bool is True
+    assert args.enabled is True
 
 
 def test_argparse_env() -> None:
@@ -54,7 +54,7 @@ def test_argparse_env() -> None:
     env = {
         "STR_ARG": "from env",
         "NUMBER": 4,
-        "BOOL": "yes",  # accepts both yes and true
+        "ENABLED": "yes",  # accepts both yes and true
     }
 
     for key, value in env.items():
@@ -64,7 +64,7 @@ def test_argparse_env() -> None:
 
     assert args.number == 4
     assert args.str_arg == "from env"
-    assert args.bool is True
+    assert args.enabled is True
 
     # Remove from environment variables
     for key in env:
@@ -74,7 +74,7 @@ def test_argparse_env() -> None:
 def test_argparse_env_ini() -> None:
     """
     --number from enviorment
-    --bool from ini
+    --enabled from ini
     --str-arg from cmdline
 
     """
@@ -95,7 +95,7 @@ def test_argparse_env_ini() -> None:
 
     assert args.number == 4
     assert args.str_arg == "cmdline"
-    assert args.bool is True
+    assert args.enabled is True
 
     # Remove from environment variables
     for key in env:

tests/test_schema.py

@@ -0,0 +1,114 @@
+""" test config """
+import os
+from typing import List, Optional
+
+from pydantic import BaseModel, Field
+
+import caep
+
+INI_TEST_FILE = os.path.join(os.path.dirname(__file__), "data/config_testdata.ini")
+
+
+class Arguments(BaseModel):
+
+    # Fields that are not specified as `Field` with description will not have
+    # any help text
+
+    str_arg: str = Field(description="Required String Argument")
+    number: int = Field(default=1, description="Integer with default value")
+    enabled: bool = Field(default=False, description="Boolean with default value")
+
+    # List fields will be separated by space as default
+    intlist: List[int] = Field(description="Space separated list of ints")
+
+    # Can optionally use "split" argument to use another value to split based on
+    strlist: List[str] = Field(description="Comma separated list of strings", split=",")
+
+
+def parse_args(
+    commandline: Optional[List[str]] = None,
+    description: str = "Program description",
+    config_id: str = "config_id",
+    config_filename: str = "config_filename",
+    section_name: str = "test",
+) -> Arguments:
+    return caep.parse(
+        Arguments,
+        description,
+        config_id,
+        config_filename,
+        section_name,
+        opts=commandline,
+    )
+
+
+def test_schema_commandline() -> None:
+    """all arguments from command line, using default for number and bool"""
+    commandline = "--str-arg test".split()
+
+    config = parse_args(commandline)
+
+    assert config.number == 1
+    assert config.str_arg == "test"
+    assert not config.enabled
+
+
+def test_schema_ini() -> None:
+    """all arguments from ini file"""
+    commandline = f"--config {INI_TEST_FILE}".split()
+
+    config = parse_args(commandline, section_name="test")
+
+    assert config.number == 3
+    assert config.str_arg == "from ini"
+    assert config.enabled is True
+
+
+def test_argparse_env() -> None:
+    """all arguments from env"""
+
+    env = {
+        "STR_ARG": "from env",
+        "NUMBER": 4,
+        "ENABLED": "yes",  # accepts both yes and true
+    }
+
+    for key, value in env.items():
+        os.environ[key] = str(value)
+
+    config = parse_args(section_name="test")
+
+    assert config.number == 4
+    assert config.str_arg == "from env"
+    assert config.enabled is True
+
+    # Remove from environment variables
+    for key in env:
+        del os.environ[key]
+
+
+def test_argparse_env_ini() -> None:
+    """
+    --number from environment
+    --bool from ini
+    --str-arg from cmdline
+
+    """
+    env = {
+        "NUMBER": 4,
+    }
+
+    for key, value in env.items():
+        os.environ[key] = str(value)
+
+    commandline = f"--config {INI_TEST_FILE} --str-arg cmdline".split()
+
+    config = parse_args(commandline, section_name="test")
+
+    assert config.number == 4
+    assert config.str_arg == "cmdline"
+    assert config.enabled is True
+
+    # Remove from environment variables
+    for key in env:
+        del os.environ[key]