httpx

Conventions

• Data classes: NamedTuple: Use NamedTuple for structured data. 2/2 structured classes use this pattern. Example context from httpx/_urlparse.py (lines 153-163):

  # the stdlib 'ipaddress' module for IP address validation.
  IPv4_STYLE_HOSTNAME = re.compile(r"^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$")
  IPv6_STYLE_HOSTNAME = re.compile(r"^\[.*\]$")
  
  
  class ParseResult(typing.NamedTuple):
      scheme: str
      userinfo: str
      host: str
      port: int | None
      path: str
  

• lowercase constant naming: Name constants using lowercase style. Example context from httpx/_multipart.py (lines 269-273):

          """
          boundary_length = len(self.boundary)
          length = 0
  
          for field in self.fields:
  

• Enum usage: Enum: Use Python enums for categorical values. Found 2 enum class(es). Types: Enum (1), IntEnum (1). Example context from httpx/_client.py (lines 120-130):

  ACCEPT_ENCODING = ", ".join(
      [key for key in SUPPORTED_DECODERS.keys() if key != "identity"]
  )
  
  
  class ClientState(enum.Enum):
      # UNOPENED:
      #   The client has been instantiated, but has not been used to send a request,
      #   or been opened by entering the context of a `with` block.
      UNOPENED = 1
      # OPENED:
  

• Custom decorator pattern: @click.option: Use custom decorator @click.option (17 usages). Example context from httpx/_main.py (lines 310-320):

      ctx.exit()
  
  
  @click.command(add_help_option=False)
  @click.argument("url", type=str)
  @click.option(
      "--method",
      "-m",
      "method",
      type=str,
      help=(
  

• Limited exception chaining: Preserve exception context: use raise X from Y or raise X from None. Example context from httpx/_decoders.py (lines 73-79):

              if was_first_attempt:
                  self.decompressor = zlib.decompressobj(-zlib.MAX_WBITS)
                  return self.decode(data)
              raise DecodingError(str(exc)) from exc
  
      def flush(self) -> bytes:
          try:
  

• Context manager usage: Manage resource lifecycles using context managers (e.g., Use context managers for resource management. 24 with statements. Types: http_client (5).). Example context from httpx/_main.py (lines 476-482):

          method = "POST" if content or data or files or json else "GET"
  
      try:
          with Client(proxy=proxy, timeout=timeout, http2=http2, verify=verify) as client:
              with client.stream(
                  method,
                  url,
  

• Configuration via os.environ direct access: Use os.environ direct access. Example context from httpx/_config.py (lines 31-37):

      import certifi
  
      if verify is True:
          if trust_env and os.environ.get("SSL_CERT_FILE"):  # pragma: nocover
              ctx = ssl.create_default_context(cafile=os.environ["SSL_CERT_FILE"])
          elif trust_env and os.environ.get("SSL_CERT_DIR"):  # pragma: nocover
              ctx = ssl.create_default_context(capath=os.environ["SSL_CERT_DIR"])
  

• High type annotation coverage: Standardize on typing: Type annotations are commonly used in this codebase. 396/396 functions have at least one type annotation.. Example context from httpx/_decoders.py (lines 32-42):

  except ImportError:  # pragma: no cover
      zstandard = None  # type: ignore
  
  
  class ContentDecoder:
      def decode(self, data: bytes) -> bytes:
          raise NotImplementedError()  # pragma: no cover
  
      def flush(self) -> bytes:
          raise NotImplementedError()  # pragma: no cover
  

• Manual validation (ValueError/TypeError): Validate inputs and parameters: Use Manual validation (ValueError/TypeError) for input validation. 17/17 validation patterns use this approach.. Example context from httpx/_urls.py (lines 95-101):

              for key, value in kwargs.items():
                  if key not in allowed:
                      message = f"{key!r} is an invalid keyword argument for URL()"
                      raise TypeError(message)
                  if value is not None and not isinstance(value, allowed[key]):
                      expected = allowed[key].__name__
                      seen = type(value).__name__