Fix style checks

freeride/affine.py

@@ -288,7 +288,7 @@ def plot(self, ax=None, textbook_style=True, max_q=None, label=True, **kwargs):
             >>> demand_curve = AffineElement(10.0, -2.0)
             >>> demand_curve.plot()
         """
-        if ax == None:
+        if ax is None:
             ax = plt.gca()
 
         # core plot
@@ -319,7 +319,7 @@ def plot(self, ax=None, textbook_style=True, max_q=None, label=True, **kwargs):
         if textbook_style:
             textbook_axes(ax)
 
-        if label == True:
+        if label:
 
             # Label Curves
             # if type(self).__name__ == 'Demand':

freeride/base.py

@@ -57,7 +57,7 @@ def __init__(self, *coef, symbols=None, domain=None):
         """
         self.set_symbols(symbols)
         self.is_undefined = coef == ([],)  # helpful in sum functions
-        if self.is_undefined == False:
+        if not self.is_undefined:
             coef = np.squeeze(np.array(coef, ndmin=1))
             super().__init__(coef, domain=None, symbol=self._symbol)
         else:

freeride/quadratic.py

@@ -87,7 +87,7 @@ def plot(self, ax=None, textbook_style=True, max_q=100, label=True, **kwargs):
         if textbook_style:
             textbook_axes(ax)
 
-        if label == True:
+        if label:
             # ax.set_ylabel("Price")
             ax.set_xlabel("Quantity")