Make xhistogram dependency optional

Author: ricardoV94

pymc_experimental/distributions/histogram_utils.py

@@ -2,7 +2,6 @@
 
 import numpy as np
 import pymc as pm
-import xhistogram.core
 from numpy.typing import ArrayLike
 
 try:
@@ -11,13 +10,21 @@
 except ImportError:
     dask = None
 
+try:
+    import xhistogram.core
+except ImportError:
+    xhistogram = None
+
 
 __all__ = ["quantile_histogram", "discrete_histogram", "histogram_approximation"]
 
 
 def quantile_histogram(
     data: ArrayLike, n_quantiles=1000, zero_inflation=False
 ) -> Dict[str, ArrayLike]:
+    if xhistogram is None:
+        raise RuntimeError("quantile_histogram requires xhistogram package")
+
     if dask and isinstance(data, (dask.dataframe.Series, dask.dataframe.DataFrame)):
         data = data.to_dask_array(lengths=True)
     if zero_inflation:
@@ -52,6 +59,9 @@ def quantile_histogram(
 
 
 def discrete_histogram(data: ArrayLike, min_count=None) -> Dict[str, ArrayLike]:
+    if xhistogram is None:
+        raise RuntimeError("discrete_histogram requires xhistogram package")
+
     if dask and isinstance(data, (dask.dataframe.Series, dask.dataframe.DataFrame)):
         data = data.to_dask_array(lengths=True)
     mid, count_uniq = np.unique(data, return_counts=True)

requirements.txt

@@ -1,2 +1 @@
 pymc>=4.0.1
-xhistogram