Changing the default value to None, adding docstring documenting and fixing extra logic.

Author: pedrompecanha

lib/matplotlib/axes/_base.py

@@ -3229,7 +3229,7 @@ def grid(self, visible=None, which='major', axis='both', **kwargs):
         if axis in ['y', 'both']:
             self.yaxis.grid(visible, which=which, **kwargs)
 
-    def ticklabel_format(self, *, axis='both', style='', scilimits=None,
+    def ticklabel_format(self, *, axis='both', style=None, scilimits=None,
                          useOffset=None, useLocale=None, useMathText=None):
         r"""
         Configure the `.ScalarFormatter` used by default for linear Axes.
@@ -3245,6 +3245,7 @@ def ticklabel_format(self, *, axis='both', style='', scilimits=None,
         style : {'sci', 'scientific', 'plain'}
             Whether to use scientific notation.
             The formatter default is to use scientific notation.
+            Sci is equivalent to scientific.
 
         scilimits : pair of ints (m, n)
             Scientific notation is used only for numbers outside the range
@@ -3283,8 +3284,11 @@ def ticklabel_format(self, *, axis='both', style='', scilimits=None,
             except (ValueError, TypeError) as err:
                 raise ValueError("scilimits must be a sequence of 2 integers"
                                  ) from err
-        STYLES = {'sci': True, 'scientific': True, 'plain': False, '': None}
-        is_sci_style = _api.check_getitem(STYLES, style=style)
+        STYLES = {'sci': True, 'scientific': True, 'plain': False}
+        if style == None:
+            is_sci_style = False
+        else:
+            is_sci_style = _api.check_getitem(STYLES, style=style)
         axis_map = {**{k: [v] for k, v in self._axis_map.items()},
                     'both': list(self._axis_map.values())}
         axises = _api.check_getitem(axis_map, axis=axis)