Add converter files exists checking

pyproject.toml

@@ -0,0 +1,58 @@
+[tool.poetry]
+name = "fb2converter_server"
+version = "0.1.0"
+description = ""
+authors = ["Kurbanov Bulat <kurbanovbul@gmail.com>"]
+
+[tool.poetry.dependencies]
+python = "^3.9"
+fastapi = "^0.70.1"
+python-multipart = "^0.0.5"
+aiofiles = "^0.8.0"
+uvicorn = {extras = ["standart"], version = "^0.16.0"}
+
+[tool.poetry.dev-dependencies]
+
+[build-system]
+requires = ["poetry-core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"
+
+[tool.black]
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.git
+  | \.vscode
+  | \venv
+  | alembic
+)/
+'''
+
+[tool.flake8]
+ignore = [
+    # Whitespace before ':' ( https://www.flake8rules.com/rules/E203.html )
+    "E203"
+]
+max-line-length=88
+max-complexity = 15
+select = "B,C,E,F,W,T4,B9"
+exclude = [
+    # No need to traverse our git directory
+    ".git",
+    # There's no value in checking cache directories
+    "__pycache__",
+    # The conf file is mostly autogenerated, ignore it
+    "src/app/alembic/*",
+    # The old directory contains Flake8 2.0
+]
+
+[tool.isort]
+profile = "black"
+only_sections = true
+force_sort_within_sections = true
+lines_after_imports = 2
+lexicographical = true
+sections = ["FUTURE", "STDLIB", "BASEFRAMEWORK", "FRAMEWORKEXT", "THIRDPARTY", "FIRSTPARTY", "LOCALFOLDER"]
+known_baseframework = ["fastapi",]
+known_frameworkext = ["starlette",]
+src_paths = ["app"]