prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Circular import error (again) in 3.4.3
  Opening a new issue as the old one (https://github.com/pyca/cryptography/issues/5756) wasn't re-opened after my comment:
  
  
  @reaperhulk
  
  Hi,
  
  still got some circular import problems here with cryptography 3.4.3 :
  
  `AttributeError: partially initialized module 'cryptography.hazmat.primitives.asymmetric.dh' has no attribute 'DHParameters' (most likely due to a circular import)`
  
  reproducer used (gencrypto.py):
  
  ```
  pip3 install -U cryptography
  Collecting cryptography
    Downloading cryptography-3.4.3-cp36-abi3-manylinux2014_x86_64.whl (3.2 MB)
       |████████████████████████████████| 3.2 MB 5.3 MB/s 
  
  
  python3 gencrypto.py
  
  Traceback (most recent call last):
    File "gencrypto.py", line 2, in <module>
      from cryptography.hazmat.primitives.asymmetric import dh
    File "/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/asymmetric/dh.py", line 11, in <module>
      from cryptography.hazmat.primitives import serialization
    File "/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/serialization/__init__.py", line 15, in <module>
      from cryptography.hazmat.primitives.serialization.base import (
    File "/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/serialization/base.py", line 28, in <module>
      def load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:
  AttributeError: partially initialized module 'cryptography.hazmat.primitives.asymmetric.dh' has no attribute 'DHParameters' (most likely due to a circular import)
  ```
  
  **gencrypto.py**
  
  ```
  import time
  from cryptography.hazmat.primitives.asymmetric import dh
  
  
  for i in [2048,3072,4096]:
      begin=time.time()
      params = dh.generate_parameters(
          generator=2,
          key_size=i,
      )
      end=time.time()
      print('took {}s for {} keysize'.format(int(end-begin), i))
  ```
  Create py.typed
  the changelog lists:
  
  > cryptography now has PEP 484 type hints on nearly all of of its public APIs. Users can begin using them to type check their code with mypy.
  
  but I'm still falling back to typeshed because this file is missing
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `src/cryptography/hazmat/primitives/serialization/base.py`
  Content:
  ```
  1 # This file is dual licensed under the terms of the Apache License, Version
  2 # 2.0, and the BSD License. See the LICENSE file in the root of this repository
  3 # for complete details.
  4 
  5 
  6 import typing
  7 
  8 from cryptography.hazmat._types import (
  9     _PRIVATE_KEY_TYPES,
  10     _PUBLIC_KEY_TYPES,
  11 )
  12 from cryptography.hazmat.backends import _get_backend
  13 from cryptography.hazmat.primitives.asymmetric import dh
  14 
  15 
  16 def load_pem_private_key(
  17     data: bytes, password: typing.Optional[bytes], backend=None
  18 ) -> _PRIVATE_KEY_TYPES:
  19     backend = _get_backend(backend)
  20     return backend.load_pem_private_key(data, password)
  21 
  22 
  23 def load_pem_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:
  24     backend = _get_backend(backend)
  25     return backend.load_pem_public_key(data)
  26 
  27 
  28 def load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:
  29     backend = _get_backend(backend)
  30     return backend.load_pem_parameters(data)
  31 
  32 
  33 def load_der_private_key(
  34     data: bytes, password: typing.Optional[bytes], backend=None
  35 ) -> _PRIVATE_KEY_TYPES:
  36     backend = _get_backend(backend)
  37     return backend.load_der_private_key(data, password)
  38 
  39 
  40 def load_der_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:
  41     backend = _get_backend(backend)
  42     return backend.load_der_public_key(data)
  43 
  44 
  45 def load_der_parameters(data: bytes, backend=None) -> dh.DHParameters:
  46     backend = _get_backend(backend)
  47     return backend.load_der_parameters(data)
  48
  ```
  
  Path: `src/cryptography/__about__.py`
  Content:
  ```
  1 # This file is dual licensed under the terms of the Apache License, Version
  2 # 2.0, and the BSD License. See the LICENSE file in the root of this repository
  3 # for complete details.
  4 
  5 
  6 __all__ = [
  7     "__title__",
  8     "__summary__",
  9     "__uri__",
  10     "__version__",
  11     "__author__",
  12     "__email__",
  13     "__license__",
  14     "__copyright__",
  15 ]
  16 
  17 __title__ = "cryptography"
  18 __summary__ = (
  19     "cryptography is a package which provides cryptographic recipes"
  20     " and primitives to Python developers."
  21 )
  22 __uri__ = "https://github.com/pyca/cryptography"
  23 
  24 __version__ = "3.4.3"
  25 
  26 __author__ = "The Python Cryptographic Authority and individual contributors"
  27 __email__ = "cryptography-dev@python.org"
  28 
  29 __license__ = "BSD or Apache License, Version 2.0"
  30 __copyright__ = "Copyright 2013-2021 {}".format(__author__)
  31
  ```
  
  Path: `vectors/cryptography_vectors/__about__.py`
  Content:
  ```
  1 # This file is dual licensed under the terms of the Apache License, Version
  2 # 2.0, and the BSD License. See the LICENSE file in the root of this repository
  3 # for complete details.
  4 
  5 __all__ = [
  6     "__title__",
  7     "__summary__",
  8     "__uri__",
  9     "__version__",
  10     "__author__",
  11     "__email__",
  12     "__license__",
  13     "__copyright__",
  14 ]
  15 
  16 __title__ = "cryptography_vectors"
  17 __summary__ = "Test vectors for the cryptography package."
  18 
  19 __uri__ = "https://github.com/pyca/cryptography"
  20 
  21 __version__ = "3.4.3"
  22 
  23 __author__ = "The Python Cryptographic Authority and individual contributors"
  24 __email__ = "cryptography-dev@python.org"
  25 
  26 __license__ = "BSD or Apache License, Version 2.0"
  27 __copyright__ = "Copyright 2013-2021 %s" % __author__
  28
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/src/cryptography/__about__.py b/src/cryptography/__about__.py
  --- a/src/cryptography/__about__.py
  +++ b/src/cryptography/__about__.py
  @@ -21,7 +21,7 @@
   )
   __uri__ = "https://github.com/pyca/cryptography"
   
  -__version__ = "3.4.3"
  +__version__ = "3.4.4"
   
   __author__ = "The Python Cryptographic Authority and individual contributors"
   __email__ = "cryptography-dev@python.org"
  diff --git a/src/cryptography/hazmat/primitives/serialization/base.py b/src/cryptography/hazmat/primitives/serialization/base.py
  --- a/src/cryptography/hazmat/primitives/serialization/base.py
  +++ b/src/cryptography/hazmat/primitives/serialization/base.py
  @@ -25,7 +25,7 @@
       return backend.load_pem_public_key(data)
   
   
  -def load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:
  +def load_pem_parameters(data: bytes, backend=None) -> "dh.DHParameters":
       backend = _get_backend(backend)
       return backend.load_pem_parameters(data)
   
  @@ -42,6 +42,6 @@
       return backend.load_der_public_key(data)
   
   
  -def load_der_parameters(data: bytes, backend=None) -> dh.DHParameters:
  +def load_der_parameters(data: bytes, backend=None) -> "dh.DHParameters":
       backend = _get_backend(backend)
       return backend.load_der_parameters(data)
  diff --git a/vectors/cryptography_vectors/__about__.py b/vectors/cryptography_vectors/__about__.py
  --- a/vectors/cryptography_vectors/__about__.py
  +++ b/vectors/cryptography_vectors/__about__.py
  @@ -18,7 +18,7 @@
   
   __uri__ = "https://github.com/pyca/cryptography"
   
  -__version__ = "3.4.3"
  +__version__ = "3.4.4"
   
   __author__ = "The Python Cryptographic Authority and individual contributors"
   __email__ = "cryptography-dev@python.org"
  
verification_info: {"golden_diff": "diff --git a/src/cryptography/__about__.py b/src/cryptography/__about__.py\n--- a/src/cryptography/__about__.py\n+++ b/src/cryptography/__about__.py\n@@ -21,7 +21,7 @@\n )\n __uri__ = \"https://github.com/pyca/cryptography\"\n \n-__version__ = \"3.4.3\"\n+__version__ = \"3.4.4\"\n \n __author__ = \"The Python Cryptographic Authority and individual contributors\"\n __email__ = \"cryptography-dev@python.org\"\ndiff --git a/src/cryptography/hazmat/primitives/serialization/base.py b/src/cryptography/hazmat/primitives/serialization/base.py\n--- a/src/cryptography/hazmat/primitives/serialization/base.py\n+++ b/src/cryptography/hazmat/primitives/serialization/base.py\n@@ -25,7 +25,7 @@\n     return backend.load_pem_public_key(data)\n \n \n-def load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:\n+def load_pem_parameters(data: bytes, backend=None) -> \"dh.DHParameters\":\n     backend = _get_backend(backend)\n     return backend.load_pem_parameters(data)\n \n@@ -42,6 +42,6 @@\n     return backend.load_der_public_key(data)\n \n \n-def load_der_parameters(data: bytes, backend=None) -> dh.DHParameters:\n+def load_der_parameters(data: bytes, backend=None) -> \"dh.DHParameters\":\n     backend = _get_backend(backend)\n     return backend.load_der_parameters(data)\ndiff --git a/vectors/cryptography_vectors/__about__.py b/vectors/cryptography_vectors/__about__.py\n--- a/vectors/cryptography_vectors/__about__.py\n+++ b/vectors/cryptography_vectors/__about__.py\n@@ -18,7 +18,7 @@\n \n __uri__ = \"https://github.com/pyca/cryptography\"\n \n-__version__ = \"3.4.3\"\n+__version__ = \"3.4.4\"\n \n __author__ = \"The Python Cryptographic Authority and individual contributors\"\n __email__ = \"cryptography-dev@python.org\"\n", "issue": "Circular import error (again) in 3.4.3\nOpening a new issue as the old one (https://github.com/pyca/cryptography/issues/5756) wasn't re-opened after my comment:\r\n\r\n\r\n@reaperhulk\r\n\r\nHi,\r\n\r\nstill got some circular import problems here with cryptography 3.4.3 :\r\n\r\n`AttributeError: partially initialized module 'cryptography.hazmat.primitives.asymmetric.dh' has no attribute 'DHParameters' (most likely due to a circular import)`\r\n\r\nreproducer used (gencrypto.py):\r\n\r\n```\r\npip3 install -U cryptography\r\nCollecting cryptography\r\n  Downloading cryptography-3.4.3-cp36-abi3-manylinux2014_x86_64.whl (3.2 MB)\r\n     |\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588\u2588| 3.2 MB 5.3 MB/s \r\n\r\n\r\npython3 gencrypto.py\r\n\r\nTraceback (most recent call last):\r\n  File \"gencrypto.py\", line 2, in <module>\r\n    from cryptography.hazmat.primitives.asymmetric import dh\r\n  File \"/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/asymmetric/dh.py\", line 11, in <module>\r\n    from cryptography.hazmat.primitives import serialization\r\n  File \"/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/serialization/__init__.py\", line 15, in <module>\r\n    from cryptography.hazmat.primitives.serialization.base import (\r\n  File \"/home/xxxxx/.local/lib/python3.8/site-packages/cryptography/hazmat/primitives/serialization/base.py\", line 28, in <module>\r\n    def load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:\r\nAttributeError: partially initialized module 'cryptography.hazmat.primitives.asymmetric.dh' has no attribute 'DHParameters' (most likely due to a circular import)\r\n```\r\n\r\n**gencrypto.py**\r\n\r\n```\r\nimport time\r\nfrom cryptography.hazmat.primitives.asymmetric import dh\r\n\r\n\r\nfor i in [2048,3072,4096]:\r\n    begin=time.time()\r\n    params = dh.generate_parameters(\r\n        generator=2,\r\n        key_size=i,\r\n    )\r\n    end=time.time()\r\n    print('took {}s for {} keysize'.format(int(end-begin), i))\r\n```\nCreate py.typed\nthe changelog lists:\r\n\r\n> cryptography now has PEP 484 type hints on nearly all of of its public APIs. Users can begin using them to type check their code with mypy.\r\n\r\nbut I'm still falling back to typeshed because this file is missing\n", "before_files": [{"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n\nimport typing\n\nfrom cryptography.hazmat._types import (\n    _PRIVATE_KEY_TYPES,\n    _PUBLIC_KEY_TYPES,\n)\nfrom cryptography.hazmat.backends import _get_backend\nfrom cryptography.hazmat.primitives.asymmetric import dh\n\n\ndef load_pem_private_key(\n    data: bytes, password: typing.Optional[bytes], backend=None\n) -> _PRIVATE_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_pem_private_key(data, password)\n\n\ndef load_pem_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_pem_public_key(data)\n\n\ndef load_pem_parameters(data: bytes, backend=None) -> dh.DHParameters:\n    backend = _get_backend(backend)\n    return backend.load_pem_parameters(data)\n\n\ndef load_der_private_key(\n    data: bytes, password: typing.Optional[bytes], backend=None\n) -> _PRIVATE_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_der_private_key(data, password)\n\n\ndef load_der_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_der_public_key(data)\n\n\ndef load_der_parameters(data: bytes, backend=None) -> dh.DHParameters:\n    backend = _get_backend(backend)\n    return backend.load_der_parameters(data)\n", "path": "src/cryptography/hazmat/primitives/serialization/base.py"}, {"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n\n__all__ = [\n    \"__title__\",\n    \"__summary__\",\n    \"__uri__\",\n    \"__version__\",\n    \"__author__\",\n    \"__email__\",\n    \"__license__\",\n    \"__copyright__\",\n]\n\n__title__ = \"cryptography\"\n__summary__ = (\n    \"cryptography is a package which provides cryptographic recipes\"\n    \" and primitives to Python developers.\"\n)\n__uri__ = \"https://github.com/pyca/cryptography\"\n\n__version__ = \"3.4.3\"\n\n__author__ = \"The Python Cryptographic Authority and individual contributors\"\n__email__ = \"cryptography-dev@python.org\"\n\n__license__ = \"BSD or Apache License, Version 2.0\"\n__copyright__ = \"Copyright 2013-2021 {}\".format(__author__)\n", "path": "src/cryptography/__about__.py"}, {"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n__all__ = [\n    \"__title__\",\n    \"__summary__\",\n    \"__uri__\",\n    \"__version__\",\n    \"__author__\",\n    \"__email__\",\n    \"__license__\",\n    \"__copyright__\",\n]\n\n__title__ = \"cryptography_vectors\"\n__summary__ = \"Test vectors for the cryptography package.\"\n\n__uri__ = \"https://github.com/pyca/cryptography\"\n\n__version__ = \"3.4.3\"\n\n__author__ = \"The Python Cryptographic Authority and individual contributors\"\n__email__ = \"cryptography-dev@python.org\"\n\n__license__ = \"BSD or Apache License, Version 2.0\"\n__copyright__ = \"Copyright 2013-2021 %s\" % __author__\n", "path": "vectors/cryptography_vectors/__about__.py"}], "after_files": [{"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n\nimport typing\n\nfrom cryptography.hazmat._types import (\n    _PRIVATE_KEY_TYPES,\n    _PUBLIC_KEY_TYPES,\n)\nfrom cryptography.hazmat.backends import _get_backend\nfrom cryptography.hazmat.primitives.asymmetric import dh\n\n\ndef load_pem_private_key(\n    data: bytes, password: typing.Optional[bytes], backend=None\n) -> _PRIVATE_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_pem_private_key(data, password)\n\n\ndef load_pem_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_pem_public_key(data)\n\n\ndef load_pem_parameters(data: bytes, backend=None) -> \"dh.DHParameters\":\n    backend = _get_backend(backend)\n    return backend.load_pem_parameters(data)\n\n\ndef load_der_private_key(\n    data: bytes, password: typing.Optional[bytes], backend=None\n) -> _PRIVATE_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_der_private_key(data, password)\n\n\ndef load_der_public_key(data: bytes, backend=None) -> _PUBLIC_KEY_TYPES:\n    backend = _get_backend(backend)\n    return backend.load_der_public_key(data)\n\n\ndef load_der_parameters(data: bytes, backend=None) -> \"dh.DHParameters\":\n    backend = _get_backend(backend)\n    return backend.load_der_parameters(data)\n", "path": "src/cryptography/hazmat/primitives/serialization/base.py"}, {"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n\n__all__ = [\n    \"__title__\",\n    \"__summary__\",\n    \"__uri__\",\n    \"__version__\",\n    \"__author__\",\n    \"__email__\",\n    \"__license__\",\n    \"__copyright__\",\n]\n\n__title__ = \"cryptography\"\n__summary__ = (\n    \"cryptography is a package which provides cryptographic recipes\"\n    \" and primitives to Python developers.\"\n)\n__uri__ = \"https://github.com/pyca/cryptography\"\n\n__version__ = \"3.4.4\"\n\n__author__ = \"The Python Cryptographic Authority and individual contributors\"\n__email__ = \"cryptography-dev@python.org\"\n\n__license__ = \"BSD or Apache License, Version 2.0\"\n__copyright__ = \"Copyright 2013-2021 {}\".format(__author__)\n", "path": "src/cryptography/__about__.py"}, {"content": "# This file is dual licensed under the terms of the Apache License, Version\n# 2.0, and the BSD License. See the LICENSE file in the root of this repository\n# for complete details.\n\n__all__ = [\n    \"__title__\",\n    \"__summary__\",\n    \"__uri__\",\n    \"__version__\",\n    \"__author__\",\n    \"__email__\",\n    \"__license__\",\n    \"__copyright__\",\n]\n\n__title__ = \"cryptography_vectors\"\n__summary__ = \"Test vectors for the cryptography package.\"\n\n__uri__ = \"https://github.com/pyca/cryptography\"\n\n__version__ = \"3.4.4\"\n\n__author__ = \"The Python Cryptographic Authority and individual contributors\"\n__email__ = \"cryptography-dev@python.org\"\n\n__license__ = \"BSD or Apache License, Version 2.0\"\n__copyright__ = \"Copyright 2013-2021 %s\" % __author__\n", "path": "vectors/cryptography_vectors/__about__.py"}]}