oop good example.

OOP-Polynomial_equation-example.py

@@ -0,0 +1,39 @@
+class Poly(object):
+    def __init__(self, coeff):
+        self.coeff = coeff
+
+    def __str__(self):
+        repres = 'P(x)= '
+        l = len(self.coeff)
+        for idx, c in enumerate(self.coeff):
+            if (c > 0):
+                repres += f'+{c}X^{l-1-idx}'
+            elif(c < 0):
+                repres += f'{c}X^{l-1-idx}'
+            elif (c == 0):
+                pass
+        return repres
+
+    def evaluate(self, x0):
+        s = 0
+        l = len(self.coeff)
+        for idx, c in enumerate(self.coeff):
+            p = l - 1 - idx
+            s += c*x0**p
+
+        return s
+
+    def __call__(self, x0,):
+        s = 0
+        l = len(self.coeff)
+        for idx, c in enumerate(self.coeff):
+            p = l - 1 - idx
+            s += c*x0**p
+
+        return s
+
+    def __len__(self):
+        return len(self.coeff)
+
+    def __getitem__(self, idx):
+        return self.coeff[idx]