From 2d34b355edb1384b1b274725252e5859f58e64be Mon Sep 17 00:00:00 2001
From: Fabian Joswig <fjosw@users.noreply.github.com>
Date: Wed, 25 Dec 2024 11:44:24 +0100
Subject: [PATCH] [Fix] Fix ruff errors and a few type annotations

---
 pyerrors/correlators.py |  2 +-
 pyerrors/misc.py        |  6 ++++--
 pyerrors/mpm.py         |  1 -
 pyerrors/obs.py         | 11 ++++++++++-
 pyerrors/roots.py       |  2 +-
 5 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/pyerrors/correlators.py b/pyerrors/correlators.py
index 74db429d..436ca6ad 100644
--- a/pyerrors/correlators.py
+++ b/pyerrors/correlators.py
@@ -7,7 +7,7 @@ import matplotlib.pyplot as plt
 import scipy.linalg
 from .obs import Obs, reweight, correlate, CObs
 from .misc import dump_object, _assert_equal_properties
-from .fits import least_squares
+from .fits import least_squares, Fit_result
 from .roots import find_root
 from . import linalg
 from numpy import float64, int64, ndarray, ufunc
diff --git a/pyerrors/misc.py b/pyerrors/misc.py
index 8832e0ef..9fe679e7 100644
--- a/pyerrors/misc.py
+++ b/pyerrors/misc.py
@@ -6,11 +6,13 @@ import matplotlib
 import matplotlib.pyplot as plt
 import pandas as pd
 import pickle
-from .obs import Obs
+from .obs import Obs, CObs
 from .version import __version__
 from numpy import float64, int64, ndarray
-from typing import List, Type, Union
+from typing import List, Type, Union, TYPE_CHECKING
 
+if TYPE_CHECKING:
+    from .correlators import Corr
 
 def print_config():
     """Print information about version of python, pyerrors and dependencies."""
diff --git a/pyerrors/mpm.py b/pyerrors/mpm.py
index b539797e..50b5b837 100644
--- a/pyerrors/mpm.py
+++ b/pyerrors/mpm.py
@@ -3,7 +3,6 @@ import numpy as np
 import scipy.linalg
 from .obs import Obs
 from .linalg import svd, eig
-from pyerrors.obs import Obs
 from typing import List
 
 
diff --git a/pyerrors/obs.py b/pyerrors/obs.py
index 44f26a7e..762f2b06 100644
--- a/pyerrors/obs.py
+++ b/pyerrors/obs.py
@@ -1,4 +1,5 @@
 from __future__ import annotations
+import sys
 import warnings
 import hashlib
 import pickle
@@ -12,7 +13,15 @@ import numdifftools as nd
 from itertools import groupby
 from .covobs import Covobs
 from numpy import bool, float64, int64, ndarray
-from typing import Any, Callable, Dict, List, Optional, Union
+from typing import Any, Callable, Dict, List, Optional, Union, TYPE_CHECKING
+
+if sys.version_info >= (3, 10):
+    from types import NotImplementedType
+else:
+    NotImplementedType = type(NotImplemented)
+
+if TYPE_CHECKING:
+    from .correlators import Corr
 
 # Improve print output of numpy.ndarrays containing Obs objects.
 np.set_printoptions(formatter={'object': lambda x: str(x)})
diff --git a/pyerrors/roots.py b/pyerrors/roots.py
index c3a9f7da..ece0e183 100644
--- a/pyerrors/roots.py
+++ b/pyerrors/roots.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 import numpy as np
 import scipy.optimize
 from autograd import jacobian
-from .obs import derived_observable
+from .obs import Obs, derived_observable
 from typing import Callable, List, Union