Use np.strings instead of the deprecated np.char

dataiter/vector.py

@@ -122,7 +122,7 @@ def as_bytes(self):
         >>> vector.as_bytes()
         """
         if self.is_string():
-            array = np.char.encode(self, "utf-8")
+            array = np.strings.encode(self, "utf-8")
             return array.view(self.__class__)
         return self.astype(bytes)
 

doc/dt.rst

@@ -2,7 +2,7 @@ dataiter.dt
 ===========
 
 The ``dt`` module contains helper functions for dealing with vectors of
-dates and datetimes, similar to ``numpy.char`` for vectors of strings.
+dates and datetimes, similar to ``numpy.strings`` for vectors of strings.
 Most of the operations are done via Python's standard library
 ``datetime`` module and subject to any limitations therein.
 

validation/generate-df.py

@@ -17,7 +17,7 @@ def read_csv(path):
         if data[name].is_string():
             # Use all lower case for strings to avoid differing
             # sorting of lower vs. upper case characters.
-            data[name] = np.char.lower(data[name])
+            data[name] = np.strings.lower(data[name])
     return data
 
 # AGGREGATE