feat: P-1.32 completed and commented

lab-3_4/P-1.32.py

@@ -3,4 +3,95 @@ Write a Python program that can simulate a simple calculator, using the console
 device. That is, each input to the calculator, be it a number, like 12.34 or 1034, or an operator, like + or =, can be
 done on a separate line. After each such input, you should output to the Python console what would be displayed on your
 calculator.
-"""
+"""
+# define a function that parses the operators tuple into actual operators and calculates result of the expression
+def calc(value1, operator, value2):
+    if operator == "+":
+        result = value1 + value2
+    elif operator == "-":
+        result = value1 - value2
+    elif operator == "*":
+        result = value1 * value2
+    elif operator == "/":
+        # handles a ZeroDivisionError with an error message
+        try:
+            result = value1 / value2
+        except ZeroDivisionError:
+            print("You can't divide by zero, enter a new divisor")
+            # exits the function cleanly so result never holds None, preventing errors
+            return None
+    return result
+# define global tuple of potential operators    
+operators = ("+", "-", "*", "/" )
+
+def calculate():
+    value1 = None
+    operator = None
+    value2 = None
+    # prompts for user input, exits program if 'q' is entered
+    while True:
+        user_input = input("Enter a number, mathematic operator (+, -, *, /) or 'q' to quit: ")
+        if user_input == "q":
+            break
+        # if user inputs '=', prints message if nothing to calculate, prints 'value1' if stored
+        elif user_input == "=":
+            if value1 is None:
+                print("Nothing to calculate")
+            elif value2 is None:
+                print(value1)
+            # otherwise calls 'calc' function to solve the expression
+            else:
+                result = calc(value1, operator, value2)
+                # if ZeroDivisionError is caught in 'calc' resets 'value2' to None
+                if result is None:
+                    value2 = None
+                # if expression is successfully solved, stores the answer in 'value1' for future use and prints it
+                else:
+                    value1 = result
+                    operator = None
+                    value2 = None
+                    print(value1)
+        # if user input is an operator and 'value2' is not set, stores the operator and prints current state of expression
+        elif user_input in operators:
+            if value2 is None:
+                operator = user_input
+                print(value1, operator)
+            # if 'value2' is set, calculates the value of stored expression
+            else:
+                result = calc(value1, operator, value2)
+                # if ZeroDivisionError is caught in 'calc' resets 'value2' to None
+                if result is None:
+                    value2 = None
+                # otherwise sets answer of stored expression to 'value1' and 'operator' to the new operator entered, sets 'value2' to None
+                else:
+                    value1 = result
+                    value2 = None
+                    operator = user_input
+                    print(value1, operator)
+        else:
+            # if no operator is stored, tries input for valid float value
+            if operator is None:
+                try:
+                    user_input = float(user_input)
+                # handle ValueError and print error message
+                except ValueError:
+                    print("Please enter a valid number or operator")
+                    continue
+                # Stores input as 'value1' and prints it
+                value1 = user_input
+                print(value1)
+            # if operator is stored, tries input for valid float value    
+            else:
+                try:
+                    user_input = float(user_input)
+                # handle ValueError and print error message    
+                except ValueError:
+                    print("Please enter a valid number or operator")
+                    continue
+                # stores input as 'value2' and prints current state of expression
+                value2 = user_input
+                print(value1, operator, value2)
+                
+
+
+calculate()