Fix PEP8

pandas/core/series.py

@@ -1402,8 +1402,8 @@ def to_string(self, buf=None, na_rep='NaN', float_format=None, header=True,
  na_rep : str, optional
  String representation of NaN to use, default 'NaN'.
  float_format : one-parameter function, optional
- Formatter function to apply to columns' elements if they are floats,
- default None.
+ Formatter function to apply to columns' elements if they are
+ floats, default None.
  header : bool, default True
  Add the Series header (index name).
  index : bool, optional