Author: Vincent Prat <vinceprat@free.fr>
Description: Fix issues with non-integer indices
--- a/astroplan/observer.py
+++ b/astroplan/observer.py
@@ -593,11 +593,11 @@
                 if tgt not in target_inds:
                     time_inds.append(tm)
                     target_inds.append(tgt)
-            target_inds = np.array(target_inds)
+            target_inds = np.array(target_inds, dtype=int)
             time_inds = np.array(time_inds)
 
-        times = [t[i:i+2] if not np.isnan(i) else np.nan for i in time_inds]
-        altitudes = [alt[i, j:j+2] if not np.isnan(j) else np.nan
+        times = [t[int(i):int(i)+2] if not np.isnan(i) else np.nan for i in time_inds]
+        altitudes = [alt[i, int(j):int(j)+2] if not np.isnan(j) else np.nan
                      for i, j in zip(target_inds, time_inds)]
 
         return times, altitudes
--- a/astroplan/scheduling.py
+++ b/astroplan/scheduling.py
@@ -526,7 +526,7 @@
             pre_filled = filled_times.reshape((2, 2))
         else:
             filled_times = Time(pre_filled.flatten())
-            pre_filled = filled_times.reshape((len(filled_times)/2, 2))
+            pre_filled = filled_times.reshape((len(filled_times)//2, 2))
         for b in blocks:
             if b.constraints is None:
                 b._all_constraints = self.constraints
