DOC: Add documentation regarding no compression in to_parquet (pandas-dev#19131)

Author: ylogx

pandas/core/frame.py

@@ -1670,8 +1670,8 @@ def to_parquet(self, fname, engine='auto', compression='snappy',
             Parquet reader library to use. If 'auto', then the option
             'io.parquet.engine' is used. If 'auto', then the first
             library to be installed is used.
-        compression : str, optional, default 'snappy'
-            compression method, includes {'gzip', 'snappy', 'brotli'}
+        compression : {'snappy', 'gzip', 'brotli', 'None'}
+            Name of the compression to use. Use ``None`` for no compression
         kwargs
             Additional keyword arguments passed to the engine
         """

pandas/io/parquet.py

@@ -218,8 +218,8 @@ def to_parquet(df, path, engine='auto', compression='snappy', **kwargs):
         Parquet reader library to use. If 'auto', then the option
         'io.parquet.engine' is used. If 'auto', then the first
         library to be installed is used.
-    compression : str, optional, default 'snappy'
-        compression method, includes {'gzip', 'snappy', 'brotli'}
+    compression : {'snappy', 'gzip', 'brotli', 'None'}
+        Name of the compression to use. Use ``None`` for no compression
     kwargs
         Additional keyword arguments passed to the engine
     """