Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 82 insertions, 0 deletions

diff --git a/src/arrow/python/pyarrow/builder.pxi b/src/arrow/python/pyarrow/builder.pxi
new file mode 100644
index 000000000..a34ea5412
--- /dev/null
+++ b/src/arrow/python/pyarrow/builder.pxi
@@ -0,0 +1,82 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+
+cdef class StringBuilder(_Weakrefable):
+    """
+    Builder class for UTF8 strings.
+
+    This class exposes facilities for incrementally adding string values and
+    building the null bitmap for a pyarrow.Array (type='string').
+    """
+    cdef:
+        unique_ptr[CStringBuilder] builder
+
+    def __cinit__(self, MemoryPool memory_pool=None):
+        cdef CMemoryPool* pool = maybe_unbox_memory_pool(memory_pool)
+        self.builder.reset(new CStringBuilder(pool))
+
+    def append(self, value):
+        """
+        Append a single value to the builder.
+
+        The value can either be a string/bytes object or a null value
+        (np.nan or None).
+
+        Parameters
+        ----------
+        value : string/bytes or np.nan/None
+            The value to append to the string array builder.
+        """
+        if value is None or value is np.nan:
+            self.builder.get().AppendNull()
+        elif isinstance(value, (bytes, str)):
+            self.builder.get().Append(tobytes(value))
+        else:
+            raise TypeError('StringBuilder only accepts string objects')
+
+    def append_values(self, values):
+        """
+        Append all the values from an iterable.
+
+        Parameters
+        ----------
+        values : iterable of string/bytes or np.nan/None values
+            The values to append to the string array builder.
+        """
+        for value in values:
+            self.append(value)
+
+    def finish(self):
+        """
+        Return result of builder as an Array object; also resets the builder.
+
+        Returns
+        -------
+        array : pyarrow.Array
+        """
+        cdef shared_ptr[CArray] out
+        with nogil:
+            self.builder.get().Finish(&out)
+        return pyarrow_wrap_array(out)
+
+    @property
+    def null_count(self):
+        return self.builder.get().null_count()
+
+    def __len__(self):
+        return self.builder.get().length()