regression to 0.22 and add zipfile support

Author: minggli

pandas/io/formats/csvs.py

@@ -9,7 +9,6 @@
 import numpy as np
 
 from pandas.core.dtypes.missing import notna
-from pandas.core.dtypes.inference import is_file_like
 from pandas.core.index import Index, MultiIndex
 from pandas import compat
 from pandas.compat import (StringIO, range, zip)
@@ -128,19 +127,26 @@ def save(self):
         else:
             encoding = self.encoding
 
-        # PR 21300 uses string buffer to receive csv writing and dump into
-        # file-like output with compression as option. GH 21241, 21118
-        f = StringIO()
-        if not is_file_like(self.path_or_buf):
-            # path_or_buf is path
-            path_or_buf = self.path_or_buf
-        elif hasattr(self.path_or_buf, 'name'):
-            # path_or_buf is file handle
-            path_or_buf = self.path_or_buf.name
+        if (not hasattr(self.path_or_buf, 'write') and
+                self.compression == 'zip'):
+            is_zip = True
         else:
-            # path_or_buf is file-like IO objects.
+            is_zip = False
+
+        if is_zip:
+            # zipfile doesn't support writing string to archive. uses string
+            # buffer to receive csv writing and dump into zip compression
+            # file handle. GH 21241, 21118
+            f = StringIO()
+            close = False
+        elif hasattr(self.path_or_buf, 'write'):
             f = self.path_or_buf
-            path_or_buf = None
+            close = False
+        else:
+            f, handles = _get_handle(self.path_or_buf, self.mode,
+                                     encoding=encoding,
+                                     compression=self.compression)
+            close = True
 
         try:
             writer_kwargs = dict(lineterminator=self.line_terminator,
@@ -157,17 +163,35 @@ def save(self):
             self._save()
 
         finally:
-            # GH 17778 handles zip compression for byte strings separately.
-            buf = f.getvalue()
-            if path_or_buf:
-                f, handles = _get_handle(path_or_buf, self.mode,
-                                         encoding=encoding,
-                                         compression=self.compression)
-                f.write(buf)
+            if is_zip:
+                # GH 17778 handles zip compression separately.
+                buf = f.getvalue()
+                try:
+                    self.path_or_buf.write(buf)
+                except AttributeError:
+                    f, handles = _get_handle(self.path_or_buf, self.mode,
+                                             encoding=encoding,
+                                             compression=self.compression)
+                    f.write(buf)
+                    close = True
+            if close:
                 f.close()
                 for _fh in handles:
                     _fh.close()
 
+            # GH 17778 handles zip compression for byte strings separately.
+            # if path is not None:
+            #     buf = f.getvalue()
+            #     f, handles = _get_handle(path, self.mode,
+            #                              encoding=encoding,
+            #                              compression=self.compression)
+            #     f.write(buf)
+            #
+            #     if not py2zip:
+            #         f.close()
+            #         for _fh in handles:
+            #             _fh.close()
+
     def _save_header(self):
 
         writer = self.writer