simpify if clause

Author: charlesdong1991

pandas/io/formats/csvs.py

@@ -53,7 +53,7 @@ def __init__(self, obj, path_or_buf=None, sep=",", na_rep='',
         # if index label is not explicitly called, index label is True if
         # header or index is not False; otherwise, index label is set to False
         if index_label is None:
-            if self.header is False or self.header is None or not self.index:
+            if not self.header or not self.index:
                 self.index_label = False
             else:
                 self.index_label = True