diff --git a/Pipfile b/Pipfile
new file mode 100644
index 0000000..f9e2ce2
--- /dev/null
+++ b/Pipfile
@@ -0,0 +1,13 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+
+[dev-packages]
+mypy = "*"
+autopep8 = "*"
+
+[requires]
+python_version = "3.9"
diff --git a/Pipfile.lock b/Pipfile.lock
new file mode 100644
index 0000000..054be30
--- /dev/null
+++ b/Pipfile.lock
@@ -0,0 +1,89 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "26e92a3c3dfbd901ea09f8d997b3db4156a4216a75b4d3b3822d71ce11e0467f"
+        },
+        "pipfile-spec": 6,
+        "requires": {
+            "python_version": "3.9"
+        },
+        "sources": [
+            {
+                "name": "pypi",
+                "url": "https://pypi.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {},
+    "develop": {
+        "autopep8": {
+            "hashes": [
+                "sha256:44f0932855039d2c15c4510d6df665e4730f2b8582704fa48f9c55bd3e17d979",
+                "sha256:ed77137193bbac52d029a52c59bec1b0629b5a186c495f1eb21b126ac466083f"
+            ],
+            "index": "pypi",
+            "version": "==1.6.0"
+        },
+        "mypy": {
+            "hashes": [
+                "sha256:088cd9c7904b4ad80bec811053272986611b84221835e079be5bcad029e79dd9",
+                "sha256:0aadfb2d3935988ec3815952e44058a3100499f5be5b28c34ac9d79f002a4a9a",
+                "sha256:119bed3832d961f3a880787bf621634ba042cb8dc850a7429f643508eeac97b9",
+                "sha256:1a85e280d4d217150ce8cb1a6dddffd14e753a4e0c3cf90baabb32cefa41b59e",
+                "sha256:3c4b8ca36877fc75339253721f69603a9c7fdb5d4d5a95a1a1b899d8b86a4de2",
+                "sha256:3e382b29f8e0ccf19a2df2b29a167591245df90c0b5a2542249873b5c1d78212",
+                "sha256:42c266ced41b65ed40a282c575705325fa7991af370036d3f134518336636f5b",
+                "sha256:53fd2eb27a8ee2892614370896956af2ff61254c275aaee4c230ae771cadd885",
+                "sha256:704098302473cb31a218f1775a873b376b30b4c18229421e9e9dc8916fd16150",
+                "sha256:7df1ead20c81371ccd6091fa3e2878559b5c4d4caadaf1a484cf88d93ca06703",
+                "sha256:866c41f28cee548475f146aa4d39a51cf3b6a84246969f3759cb3e9c742fc072",
+                "sha256:a155d80ea6cee511a3694b108c4494a39f42de11ee4e61e72bc424c490e46457",
+                "sha256:adaeee09bfde366d2c13fe6093a7df5df83c9a2ba98638c7d76b010694db760e",
+                "sha256:b6fb13123aeef4a3abbcfd7e71773ff3ff1526a7d3dc538f3929a49b42be03f0",
+                "sha256:b94e4b785e304a04ea0828759172a15add27088520dc7e49ceade7834275bedb",
+                "sha256:c0df2d30ed496a08de5daed2a9ea807d07c21ae0ab23acf541ab88c24b26ab97",
+                "sha256:c6c2602dffb74867498f86e6129fd52a2770c48b7cd3ece77ada4fa38f94eba8",
+                "sha256:ceb6e0a6e27fb364fb3853389607cf7eb3a126ad335790fa1e14ed02fba50811",
+                "sha256:d9dd839eb0dc1bbe866a288ba3c1afc33a202015d2ad83b31e875b5905a079b6",
+                "sha256:e4dab234478e3bd3ce83bac4193b2ecd9cf94e720ddd95ce69840273bf44f6de",
+                "sha256:ec4e0cd079db280b6bdabdc807047ff3e199f334050db5cbb91ba3e959a67504",
+                "sha256:ecd2c3fe726758037234c93df7e98deb257fd15c24c9180dacf1ef829da5f921",
+                "sha256:ef565033fa5a958e62796867b1df10c40263ea9ded87164d67572834e57a174d"
+            ],
+            "index": "pypi",
+            "version": "==0.910"
+        },
+        "mypy-extensions": {
+            "hashes": [
+                "sha256:090fedd75945a69ae91ce1303b5824f428daf5a028d2f6ab8a299250a846f15d",
+                "sha256:2d82818f5bb3e369420cb3c4060a7970edba416647068eb4c5343488a6c604a8"
+            ],
+            "version": "==0.4.3"
+        },
+        "pycodestyle": {
+            "hashes": [
+                "sha256:720f8b39dde8b293825e7ff02c475f3077124006db4f440dcbc9a20b76548a20",
+                "sha256:eddd5847ef438ea1c7870ca7eb78a9d47ce0cdb4851a5523949f2601d0cbbe7f"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
+            "version": "==2.8.0"
+        },
+        "toml": {
+            "hashes": [
+                "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b",
+                "sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f"
+            ],
+            "markers": "python_version >= '2.6' and python_version not in '3.0, 3.1, 3.2'",
+            "version": "==0.10.2"
+        },
+        "typing-extensions": {
+            "hashes": [
+                "sha256:4ca091dea149f945ec56afb48dae714f21e8692ef22a395223bcd328961b6a0e",
+                "sha256:7f001e5ac290a0c0401508864c7ec868be4e701886d5b573a9528ed3973d9d3b"
+            ],
+            "markers": "python_version >= '3.6'",
+            "version": "==4.0.1"
+        }
+    }
+}