Added comparison function as histogram operation

README.md

@@ -127,6 +127,7 @@ histograms can be plotted via any compatible library, such as [mplhep][].
   * `.kind`: Either `bh.Kind.COUNT` or `bh.Kind.MEAN`, depending on storage
   * `.sum(flow=False)`: The total count of all bins
   * `.project(ax1, ax2, ...)`: Project down to listed axis (numbers). Can also reorder axes.
+  * `.compare(second_hist)`: Compare the histogram with another histogram
   * `.to_numpy(flow=False, view=False)`: Convert to a NumPy style tuple (with or without under/overflow bins)
   * `.view(flow=False)`: Get a view on the bin contents (with or without under/overflow bins)
   * `.values(flow=False)`: Get a view on the values (counts or means, depending on storage)

src/boost_histogram/_internal/hist.py

@@ -1,6 +1,7 @@
 import collections.abc
 import copy
 import logging
+import re
 import threading
 import typing
 import warnings
@@ -337,6 +338,20 @@ def ndim(self) -> int:
         """
         return self._hist.rank()
 
+    def compare(self, hist2) -> bool:
+        if np.allclose(self.view().shape, hist2.view().shape):
+            if np.allclose(self.view(), hist2.view()):
+                if np.allclose(self.variances(), hist2.variances()):
+                    if (
+                        re.search("(?<=storage=).*", str(self.view))[0].split("(")[0]
+                        == re.search("(?<=storage=).*", str(hist2.view))[0].split("(")[
+                            0
+                        ]
+                    ):
+                        if list(self.axes) == list(hist2.axes):
+                            return True
+        return False
+
     def view(
         self, flow: bool = False
     ) -> Union["np.typing.NDArray[Any]", WeightedSumView, WeightedMeanView, MeanView]: