1 files changed, 51 insertions, 0 deletions
diff --git a/vk/utils/io.py b/vk/utils/io.py
new file mode 100644
index 0000000..bb8eef9
--- /dev/null
+++ b/vk/utils/io.py
@@ -0,0 +1,51 @@
+# Copyright (c) 2017 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "VK scripts" project.
+# For details, see https://github.com/egor-tensin/vk-scripts.
+# Distributed under the MIT License.
+
+from contextlib import contextmanager
+import csv
+import json
+import sys
+
+
+class FileWriterJSON:
+    def __init__(self, fd=sys.stdout):
+        self._fd = fd
+
+    def write(self, something):
+        self._fd.write(json.dumps(something, indent=3, ensure_ascii=False))
+        self._fd.write('\n')
+
+
+class FileWriterCSV:
+    def __init__(self, fd=sys.stdout):
+        self._writer = csv.writer(fd, lineterminator='\n')
+
+    @staticmethod
+    def _convert_row_old_python(row):
+        if isinstance(row, (list, tuple)):
+            return row
+        return list(row)
+
+    def write_row(self, row):
+        if sys.version_info < (3, 5):
+            row = self._convert_row_old_python(row)
+        self._writer.writerow(row)
+
+
+@contextmanager
+def _open_file(path=None, default=None, **kwargs):
+    if path is None:
+        yield default
+    else:
+        with open(path, **kwargs) as fd:
+            yield fd
+
+
+def open_output_text_file(path=None):
+    return _open_file(path, default=sys.stdout, mode='w', encoding='utf-8')
+
+
+def open_output_binary_file(path=None):
+    return _open_file(path, default=sys.stdout, mode='wb')