00dict_args.py

import typing as t
import sys
import argparse
import json


def JSONDictType(
    filename_or_content: str, *, prefix: str = "file://"
) -> t.Dict[str, t.Any]:
    try:
        if filename_or_content.startswith(prefix):
            with open(filename_or_content[len(prefix) :]) as rf:
                d: t.Dict[str, t.Any] = json.load(rf)
        else:
            d = json.loads(filename_or_content)
        return d
    except (ValueError, FileNotFoundError) as e:
        raise argparse.ArgumentTypeError(str(e))


parser = argparse.ArgumentParser()
parser.add_argument("--config", type=JSONDictType)

args = parser.parse_args()
json.dump(args.config, sys.stdout, indent=2)
print("")

0102.diff

--- 01pydantic.py	2020-01-18 19:53:30.000000000 +0900
+++ 02pydantic-with-schema.py	2020-01-18 19:57:50.000000000 +0900
@@ -22,15 +22,21 @@
 
 
 parser = argparse.ArgumentParser()
-parser.add_argument("--config", type=ConfigType)
-
+parser.add_argument("--config", type=ConfigType, required=False)
+parser.add_argument("--show-schema", action="store_true")
 args = parser.parse_args()
 
 
-def use(config: Config) -> None:
-    # ここでconfigがConfigと認識されるのは地味に便利
-    # t.TYPE_CHECKING and reveal_type(config)
-    print(args)
+if args.show_schema:
+    from pydantic.schema import schema
+
+    toplevel_schema = schema([Config])
+    print(json.dumps(toplevel_schema, indent=2, ensure_ascii=False))
+    parser.exit()
+
+
+def use(config: "Config") -> None:
+    print(config)
 
 
 use(args.config)

01pydantic.py

import typing as t
import json
import argparse
from pydantic.error_wrappers import ValidationError
from config import Config


def ConfigType(filename_or_content: str, *, prefix: str = "file://") -> Config:
    try:
        if filename_or_content.startswith(prefix):
            with open(filename_or_content[len(prefix) :]) as rf:
                d = json.load(rf)
        else:
            d = json.loads(filename_or_content)
    except (ValueError, FileNotFoundError) as e:
        raise argparse.ArgumentTypeError(str(e))

    try:
        return Config(**d)
    except ValidationError as e:
        raise argparse.ArgumentTypeError(str(e))


parser = argparse.ArgumentParser()
parser.add_argument("--config", type=ConfigType)

args = parser.parse_args()


def use(config: Config) -> None:
    # ここでconfigがConfigと認識されるのは地味に便利
    # t.TYPE_CHECKING and reveal_type(config)
    print(args)


use(args.config)

0203.diff

--- 02pydantic-with-schema.py	2020-01-18 19:57:50.000000000 +0900
+++ 03pydantic-with-schema.py	2020-01-18 20:06:29.000000000 +0900
@@ -1,11 +1,15 @@
 import typing as t
 import json
 import argparse
-from pydantic.error_wrappers import ValidationError
-from config import Config
 
+if t.TYPE_CHECKING:
+    from config import Config
+
+
+def ConfigType(filename_or_content: str, *, prefix: str = "file://") -> "Config":
+    from pydantic.error_wrappers import ValidationError
+    from config import Config
 
-def ConfigType(filename_or_content: str, *, prefix: str = "file://") -> Config:
     try:
         if filename_or_content.startswith(prefix):
             with open(filename_or_content[len(prefix) :]) as rf:
@@ -21,6 +25,14 @@
         raise argparse.ArgumentTypeError(str(e))
 
 
+def show_schema() -> None:
+    from config import Config
+    from pydantic.schema import schema
+
+    toplevel_schema = schema([Config])
+    print(json.dumps(toplevel_schema, indent=2, ensure_ascii=False))
+
+
 parser = argparse.ArgumentParser()
 parser.add_argument("--config", type=ConfigType, required=False)
 parser.add_argument("--show-schema", action="store_true")
@@ -28,10 +40,7 @@
 
 
 if args.show_schema:
-    from pydantic.schema import schema
-
-    toplevel_schema = schema([Config])
-    print(json.dumps(toplevel_schema, indent=2, ensure_ascii=False))
+    show_schema()
     parser.exit()
 
 

02pydantic-with-schema.py

import typing as t
import json
import argparse
from pydantic.error_wrappers import ValidationError
from config import Config


def ConfigType(filename_or_content: str, *, prefix: str = "file://") -> Config:
    try:
        if filename_or_content.startswith(prefix):
            with open(filename_or_content[len(prefix) :]) as rf:
                d = json.load(rf)
        else:
            d = json.loads(filename_or_content)
    except (ValueError, FileNotFoundError) as e:
        raise argparse.ArgumentTypeError(str(e))

    try:
        return Config(**d)
    except ValidationError as e:
        raise argparse.ArgumentTypeError(str(e))


parser = argparse.ArgumentParser()
parser.add_argument("--config", type=ConfigType, required=False)
parser.add_argument("--show-schema", action="store_true")
args = parser.parse_args()


if args.show_schema:
    from pydantic.schema import schema

    toplevel_schema = schema([Config])
    print(json.dumps(toplevel_schema, indent=2, ensure_ascii=False))
    parser.exit()


def use(config: "Config") -> None:
    print(config)


use(args.config)

03pydantic-with-schema.py

import typing as t
import json
import argparse

if t.TYPE_CHECKING:
    from config import Config


def ConfigType(filename_or_content: str, *, prefix: str = "file://") -> "Config":
    from pydantic.error_wrappers import ValidationError
    from config import Config

    try:
        if filename_or_content.startswith(prefix):
            with open(filename_or_content[len(prefix) :]) as rf:
                d = json.load(rf)
        else:
            d = json.loads(filename_or_content)
    except (ValueError, FileNotFoundError) as e:
        raise argparse.ArgumentTypeError(str(e))

    try:
        return Config(**d)
    except ValidationError as e:
        raise argparse.ArgumentTypeError(str(e))


def show_schema() -> None:
    from config import Config
    from pydantic.schema import schema

    toplevel_schema = schema([Config])
    print(json.dumps(toplevel_schema, indent=2, ensure_ascii=False))


parser = argparse.ArgumentParser()
parser.add_argument("--config", type=ConfigType, required=False)
parser.add_argument("--show-schema", action="store_true")
args = parser.parse_args()


if args.show_schema:
    show_schema()
    parser.exit()


def use(config: "Config") -> None:
    print(config)


use(args.config)

config-ng.json

{
  "thirdparty": {
    "xxx": {
      "token": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    },
    "zzz": {
      "clientId": "xxxxxxxxxx",
      "clientSecret": "xxxxxxxxxxxxxxxxxxxx"
    }
  }
}

config.json

{
  "main": {
    "db": "sqlite://:memory"
  },
  "thirdparty": {
    "xxx": {
      "token": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    },
    "zzz": {
      "clientId": "xxxxxxxxxx",
      "clientSecret": "xxxxxxxxxxxxxxxxxxxx"
    }
  }
}

Makefile

00:
	python $(shell echo $@*.py) --config='{"main": {"db": "sqlite://:memory:"}}'
	python $(shell echo $@*.py) --config=file://config.json
	python $(shell echo $@*.py) --config=file://config-ng.json
	python $(shell echo $@*.py) --config=file://missing.json
01:
	python $(shell echo $@*.py) --config='{"main": {"db": "sqlite://:memory:"}}'
	python $(shell echo $@*.py) --config=file://config.json
	python $(shell echo $@*.py) --config=file://config-ng.json || exit 0
	python $(shell echo $@*.py) --config=file://missing.json
02:
	python $(shell echo $@*.py) --config=file://config.json
	python $(shell echo $@*.py) --config='{"main": {"db": "sqlite://:memory:"}}'
	python $(shell echo $@*.py) --config=file://config-ng.json || exit 0
	python $(shell echo $@*.py) --config=file://missing.json || exit 0
	python $(shell echo $@*.py) --show-schema
03:
	python $(shell echo $@*.py) --config='{"main": {"db": "sqlite://:memory:"}}'
	python $(shell echo $@*.py) --config=file://config.json
	python $(shell echo $@*.py) --config=file://config-ng.json

diff:
	diff -u 01*.py 02*.py > 0102.diff || exit 0
	diff -u 02*.py 03*.py > 0203.diff || exit 0
.PHONY: diff

schema.json

{
  "definitions": {
    "MainConfig": {
      "title": "MainConfig",
      "type": "object",
      "properties": {
        "db": {
          "title": "Db",
          "type": "string"
        }
      },
      "required": [
        "db"
      ]
    },
    "XXXConfig": {
      "title": "XXXConfig",
      "type": "object",
      "properties": {
        "token": {
          "title": "Token",
          "type": "string"
        }
      },
      "required": [
        "token"
      ]
    },
    "ZZZConfig": {
      "title": "ZZZConfig",
      "type": "object",
      "properties": {
        "clientId": {
          "title": "Clientid",
          "type": "string"
        },
        "clientSecret": {
          "title": "Clientsecret",
          "type": "string"
        }
      },
      "required": [
        "clientId",
        "clientSecret"
      ]
    },
    "ThirdpartyConfig": {
      "title": "ThirdpartyConfig",
      "type": "object",
      "properties": {
        "xxx": {
          "$ref": "#/definitions/XXXConfig"
        },
        "zzz": {
          "$ref": "#/definitions/ZZZConfig"
        }
      },
      "required": [
        "xxx",
        "zzz"
      ]
    },
    "Config": {
      "title": "Config",
      "type": "object",
      "properties": {
        "main": {
          "$ref": "#/definitions/MainConfig"
        },
        "thirdparty": {
          "$ref": "#/definitions/ThirdpartyConfig"
        }
      },
      "required": [
        "main"
      ]
    }
  }
}