chore(Python): added interpolation search file (#334)

algorithms/Python/README.md

@@ -21,6 +21,7 @@
 2. [Jump Search](searching/jump_search.py)
 3. [Linear Search](searching/linear_search.py)
 4. [Ternary Search](searching/ternary_search.py)
+5. [Interpolation Search](searching/interpolation_search.py)
 
 ## Sorting
 1. [Bubble Sort](sorting/bubble_sort.py)
@@ -44,4 +45,3 @@
 1. [Print Fibonacci Series Up To N-th Term](dynamic_programming/fibonacci_series.py)
 2. [Sum Up To N-th Term Of Fibonacci Series](dynamic_programming/fibonacci_series_sum.py )
 3. [N-th Term Of Fibonacci Series](dynamic_programming/fibonacci_series_nth_term.py)
-

algorithms/Python/searching/interpolation_search.py

@@ -0,0 +1,45 @@
+def interpolation_search(array, x):
+    """
+    Use interpolation search to find a specified integer
+    """
+    if isinstance(x, int) and isinstance(array, list): # check that x is integer and array is list
+        if len(array) < 1: # if array length is less than 1 print message
+            return False
+        elif len(array) == 1 and x in array: # if x is only element of array return index 0
+            return 0
+        elif len(array) > 1 and x in array: # search if array length > 1 and x is in the array
+            min = 0
+            max = len(array) - 1
+            while min <= max:
+                if array[min] == array[max] == x:
+                    return min
+                elif array[min] == array[max] != x:
+                    return False
+                else:
+                    p = int(min + (x-array[min])*(max-min) / (array[max]-array[min]))
+                    if array[p] == x:
+                        return p
+                    elif x < array[p]:
+                        max = p - 1
+                        continue
+                    elif x > array[p]:
+                        min = p + 1
+                        continue
+        else:
+            return False # if x is not in array return false
+    else:
+        raise Exception('Please make sure x is an integer and array is a list.')
+
+
+if __name__ == '__main__':
+    tests = [
+    ([1,4,7,10,13,16], 13),
+    ([1,4,7,10,13,16], 11),
+    ([1,1,1,1,1,1], 1),
+    ([0,0,0,1,1,1,1,1,1,2,3,4,5], 1),
+    ([24], 24),
+    ([], 24)
+    ]
+
+    for test in tests:
+        print(interpolation_search(test[0], test[1]))