added yosh loop to test case

app/test/test_example.py

@@ -1,4 +1,6 @@
 # content of example.py
+from pulp import LpProblem, LpVariable, LpMinimize, LpStatus, lpSum
+
 def func(x):
     return x + 1
 
@@ -8,4 +10,51 @@ def test_pass():
 
 
 def test_failure():
-    assert func(3) == 5
+    assert func(3) == 5
+
+def yosh_loop():
+    Items = [1,2,3,4,5]
+    tif = {
+        1: 0.2,
+        2: 0.5,
+        3: 0.3,
+        4: 0.8,
+        5: 0.1
+    }
+    iif = {
+        1: 0.09,
+        2: 0.2,
+        3: 0.113,
+        4: 0.3,
+        5: 0.1
+    }
+    drift = 0.0
+    drift_limit = 0.2
+    iif_target = 0.5
+    tif_target = 0.9
+    item_vars = LpVariable.dicts("Item", Items, cat="Binary")
+
+    while drift <= drift_limit:
+        prob = LpProblem("tif_tcc_test", LpMinimize)
+        prob += lpSum([(tif[i] + iif[i]) * item_vars[i] for i in Items]), "TifTccSum"
+        prob += lpSum([item_vars[i] for i in Items]) == 3, "TotalItems"
+        prob += lpSum([tif[i] * item_vars[i] for i in Items]) >= tif_target - (tif_target * drift), 'TifMin'
+        prob += lpSum([tif[i] * item_vars[i] for i in Items]) <= tif_target  + (tif_target * drift), 'TifMax'
+        prob += lpSum([iif[i] * item_vars[i] for i in Items]) >= iif_target - (iif_target * drift), 'TccMin'
+        prob += lpSum([iif[i] * item_vars[i] for i in Items]) <= iif_target + (iif_target * drift), 'TccMax'
+
+        prob.solve()
+
+        if LpStatus[prob.status] == "Infeasible":
+            for v in prob.variables():
+                print(v.name, "=", v.varValue)
+
+            drift += 0.02
+        else:
+            for v in prob.variables():
+                print(v.name, "=", v.varValue)
+            break
+
+def test_solver():
+    print(yosh_loop())
+    assert yosh_loop() == 'Solved'