Update page 'Day2 Homework -Karen'

Day2 Homework -Karen.md

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+**1. Annotate the following python expressions with the specific types of each literal, as well as the overall return value:**
+
+    ```
+     i = 3   # the literal "3" and the overall return "i" are both integer as `int`
+     f = 3.0   # the literal "3.0" and the overal return "f" are both floating-point literal of type `float`
+     c = 3+3i   # the literal "3" is an integer as `int` while the literal "3i" is a complex literal with 0 as the real part and the 3i as the imaginary part; the overal return c is a complex number of type `complex`
+     b = b'abcdefg'   # the literal "b'abcdefg'" and the overall return "b" are both bytes literal of type `bytes`
+     s = 'abcdefg'   # the literal "'abcdegf'" and the overall return "s" are both string literal of type `str`
+     s = "abcdefg"   # the literal ""abcdegf"" and the overall return "s" are both string literal of type `str`
+    ```
+❓ I have a question for the function 'c' as it gives a syntax error when I enter it in Python saying invalid decimal literal, so how can we enter such kind of complex number of type `complex` in python?
+
+**2. For each of the types string, bytestring, integer, floating point, and imaginary literals, construct a 5x5 table showing what happens when the character "0" or number 0 is compared to each other type.**  
+
+```ruby
+# Define literals
+str_literal = "12345"
+bytes_literal = b"12345"
+int_literal = 12345
+float_literal = 123.45
+imag_literal = 123+45j
+
+# Define comparison function
+def compare(literal):
+    # Create table header
+    print(f"\nComparison table for {type(literal).__name__} literals:\n")
+    print(f"{'':10} {'0':^5} {literal[0]:^5} {literal[1]:^5} {literal[2]:^5} {literal[3]:^5} {literal[4]:^5}")
+
+    # Compare each element in the literal to 0
+    for i, elem in enumerate(literal):
+        is_equal = "==" if elem == 0 else "!="
+        print(f"{elem:<10} {is_equal:^5} {0:^5} {is_equal:^5} {i:^5} {is_equal:^5} {i+1:^5} {is_equal:^5} {i+2:^5} {is_equal:^5} {i+3:^5} {is_equal:^5} {i+4:^5}")
+
+# Call comparison function for each type of literal
+compare(str_literal)
+compare(bytes_literal)
+compare(int_literal)
+compare(float_literal)
+compare(imag_literal)
+
+Comparison table for str literals:
+
+           0     1     2     3     4   
+1          !=    ==    !=    !=    !=  
+2          !=    !=    ==    !=    !=  
+3          !=    !=    !=    ==    !=  
+4          !=    !=    !=    !=    ==  
+5          !=    !=    !=    !=    !=  
+
+Comparison table for bytes literals:
+
+           0     1     2     3     4   
+49         !=    ==    !=    !=    !=  
+50         !=    !=    ==    !=    !=  
+51         !=    !=    !=    ==    !=  
+52         !=    !=    !=    !=    ==  
+53         !=    !=    !=    !=    !=  
+
+Comparison table for int literals:
+
+           0     1     2     3     4   
+12345      !=    !=    !=    !=    !=  
+
+Comparison table for float literals:
+
+           0     1     2     3     4   
+123.45     !=    !=    !=    !=    !=  
+
+Comparison table for complex literals:
+
+           0     1     2     3     4   
+(123+45j)  !=    !=    !=    !=    !=  
+```
+
+
+
+**3. Now do the same thing for the + and == operators for each pair of types in two other 5x5 tables.**  
+
+
+
+**4. Write a small program that uses the AST module to open the lexer/parser example, and dumps the resulting AST.  See if there are any arguments to the parse method which make the output easier to read.**  
+
+
+
+**5. What does this do?  `print("\007")`  Can you figure out why?**  
+
+**6. What does this do?  `print("abcdefg\rhijklmnop")`  Can you figure out why?**  
+
+**7. This is an HTTP server.  Run it and connect to http://localhost:8000 .  Why doesn't this do the same thing as what you see above?  (don't forget to shut down the HTTP server afterward.)**
+
+    ```
+    import http.server
+    import socketserver
+    from urllib.parse import urlparse, parse_qs
+
+    class MyRequestHandler(http.server.SimpleHTTPRequestHandler):
+        def do_GET(self):
+            self.send_response(200)
+            self.send_header('Content-type', 'text/plain')
+            self.end_headers()
+            output_string = "abcdefg\rhijklmnop"
+            self.wfile.write(output_string.encode())
+
+    PORT = 8000
+    Handler = MyRequestHandler
+    httpd = socketserver.TCPServer(("", PORT), Handler)
+    print(f"Serving on port {PORT}")
+
+    httpd.serve_forever()
+    ```
+
+**8. Think of a way someone might try to commit a crime or hide an embezzlement scheme using the answers to the above two questions.  Hint: applications usually output on web pages, but developers and system administrators usually troubleshoot in the console.**
+**9. Think of how you would do input validation to prevent such a crime.  Replace the code REPLACE ME here so the tests pass:**
+
+```
+def validate(str):
+    for char in str:
+        if REPLACE ME:
+            raise ValueError("Crime detected!")
+
+try:
+    validate("abcdefg")
+    print("✅ test1 pass!")
+except:
+    print("❌ test1 pass!")
+
+try:
+    validate("abcdefg\rhijklmnop")
+    print("❌ test2 fail!")
+except ValueError as err:
+    print("✅ test2 pass!")
+```
+
+