BUG/MAINT: Remove special handling of 0d arrays and scalars in interp

These are now handled generically by the underlying C function

This fixes the period argument for 0d arrays.

Now never returns a pure-python scalar, which matches the behaviour of most of numpy.

Rework of b66a200a4a1e98f1955c8a774e4ebfb4588dab5b

1 files changed, 3 insertions, 16 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index 391c47a06..504280cef 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -1255,23 +1255,13 @@ def interp(x, xp, fp, left=None, right=None, period=None):
         interp_func = compiled_interp
         input_dtype = np.float64
 
-    if period is None:
-        if isinstance(x, (float, int, number)):
-            return interp_func([x], xp, fp, left, right).item()
-        elif isinstance(x, np.ndarray) and x.ndim == 0:
-            return interp_func([x], xp, fp, left, right).item()
-        else:
-            return interp_func(x, xp, fp, left, right)
-    else:
+    if period is not None:
         if period == 0:
             raise ValueError("period must be a non-zero value")
         period = abs(period)
         left = None
         right = None
-        return_array = True
-        if isinstance(x, (float, int, number)):
-            return_array = False
-            x = [x]
+
         x = np.asarray(x, dtype=np.float64)
         xp = np.asarray(xp, dtype=np.float64)
         fp = np.asarray(fp, dtype=input_dtype)
@@ -1289,10 +1279,7 @@ def interp(x, xp, fp, left=None, right=None, period=None):
         xp = np.concatenate((xp[-1:]-period, xp, xp[0:1]+period))
         fp = np.concatenate((fp[-1:], fp, fp[0:1]))
 
-        if return_array:
-            return interp_func(x, xp, fp, left, right)
-        else:
-            return interp_func(x, xp, fp, left, right).item()
+    return interp_func(x, xp, fp, left, right)
 
 
 def angle(z, deg=0):