pcewebpython · KRTstudent · Apr 20, 2020
diff --git a/calculator.py b/calculator.py
@@ -1,33 +1,25 @@
 """
 For your homework this week, you'll be creating a wsgi application of
 your own.
-
 You'll create an online calculator that can perform several operations.
-
 You'll need to support:
-
   * Addition
   * Subtractions
   * Multiplication
   * Division
-
 Your users should be able to send appropriate requests and get back
 proper responses. For example, if I open a browser to your wsgi
 application at `http://localhost:8080/multiple/3/5' then the response
 body in my browser should be `15`.
-
 Consider the following URL/Response body pairs as tests:
-
 ```
   http://localhost:8080/multiply/3/5   => 15
   http://localhost:8080/add/23/42      => 65
   http://localhost:8080/subtract/23/42 => -19
   http://localhost:8080/divide/22/11   => 2
   http://localhost:8080/               => <html>Here's how to use this page...</html>
 ```
-
 To submit your homework:
-
   * Fork this repository (Session03).
   * Edit this file to meet the homework requirements.
   * Your script should be runnable using `$ python calculator.py`
@@ -37,21 +29,47 @@
     that explains how to perform calculations.
   * Commit and push your changes to your fork.
   * Submit a link to your Session03 fork repository!
-
-
 """
+import traceback
 
+# TODO: Add functions for handling more arithmetic operations.
+
+def home():
+    """ Explain how to use this website """
+    text = '''
+    <h1>How to use this website:</h1>
+    <p>Use an operand extension followed by two values to calculate the result </p>
+    <p>EG: "localhost:8080/add/10/15" will result in 25 </p>
+    '''
+    return text
 
 def add(*args):
     """ Returns a STRING with the sum of the arguments """
-
     # TODO: Fill sum with the correct value, based on the
     # args provided.
-    sum = "0"
-
-    return sum
+    result = int(args[0]) + int(args[1])
+    return str(result)
 
-# TODO: Add functions for handling more arithmetic operations.
+def subtract(*args):
+    """ Returns a STRING with the sum of the arguments """
+    # TODO: Fill sum with the correct value, based on the
+    # args provided.
+    result = int(args[0]) - int(args[1])
+    return str(result)
+
+def multiply(*args):
+    """ Returns a STRING with the sum of the arguments """
+    # TODO: Fill sum with the correct value, based on the
+    # args provided.
+    result = int(args[0]) * int(args[1])
+    return str(result)
+
+def divide(*args):
+    """ Returns a STRING with the sum of the arguments """
+    # TODO: Fill sum with the correct value, based on the
+    # args provided.
+    result = int(args[0]) / int(args[1])
+    return str(result)
 
 def resolve_path(path):
     """
@@ -63,11 +81,27 @@ def resolve_path(path):
     # examples provide the correct *syntax*, but you should
     # determine the actual values of func and args using the
     # path.
-    func = add
-    args = ['25', '32']
-
+    funcs = {
+            '': home,
+            'add': add,
+            'subtract': subtract,
+            'multiply': multiply,
+            'divide': divide,
+            }
+
+    path = path.strip('/').split('/')
+
+    func_name = path[0]
+    args = path[1:]
+
+    try:
+        func = funcs[func_name]
+    except KeyError:
+        raise NameError
+
     return func, args
 
+
 def application(environ, start_response):
     # TODO: Your application code from the book database
     # work here as well! Remember that your application must
@@ -76,9 +110,30 @@ def application(environ, start_response):
     #
     # TODO (bonus): Add error handling for a user attempting
     # to divide by zero.
-    pass
+    headers = [("Content-type", "text/html")]
+    try:
+        path = environ.get('PATH_INFO', None)
+        if path is None:
+            raise NameError
+        func, args = resolve_path(path)
+        body = func(*args)
+        status = "200 OK"
+    except NameError:
+        status = "404 Not Found"
+        body = "<h1>Not Found</h1>"
+    except Exception:
+        status = "500 Internal Server Error"
+        body = "<h1>Internal Server Error</h1>"
+        print(traceback.format_exc())
+    finally:
+        headers.append(('Content-length', str(len(body))))
+        start_response(status, headers)
+        return [body.encode('utf8')]
+
 
 if __name__ == '__main__':
     # TODO: Insert the same boilerplate wsgiref simple
     # server creation that you used in the book database.
-    pass
+    from wsgiref.simple_server import make_server
+    srv = make_server('localhost', 8080, application)
+    srv.serve_forever()