added calculator susccesfully

Author: nancy-singh10

python/calculator_.py

@@ -0,0 +1,36 @@
+def add(P, Q):    
+   # This function is used for adding two numbers   
+   return P + Q   
+def subtract(P, Q):   
+   # This function is used for subtracting two numbers   
+   return P - Q   
+def multiply(P, Q):   
+   # This function is used for multiplying two numbers   
+   return P * Q   
+def divide(P, Q):   
+   # This function is used for dividing two numbers    
+   return P / Q    
+# Now we will take inputs from the user    
+print ("Please select the operation.")    
+print ("a. Add")    
+print ("b. Subtract")    
+print ("c. Multiply")    
+print ("d. Divide")    
+    
+choice = input("Please enter choice (a/ b/ c/ d): ")    
+    
+num_1 = int (input ("Please enter the first number: "))    
+num_2 = int (input ("Please enter the second number: "))    
+    
+if choice == 'a':    
+   print (num_1, " + ", num_2, " = ", add(num_1, num_2))    
+    
+elif choice == 'b':    
+   print (num_1, " - ", num_2, " = ", subtract(num_1, num_2))    
+    
+elif choice == 'c':    
+   print (num1, " * ", num2, " = ", multiply(num1, num2))    
+elif choice == 'd':    
+   print (num_1, " / ", num_2, " = ", divide(num_1, num_2))    
+else:    
+   print ("This is an invalid input")