Update code to use print formatting.

bitshift_example_1.py

@@ -21,4 +21,4 @@
     else:
         bit_value = 0
 
-    print("Bit position {:2} is {} which is worth {:2}".format(bit_pos, bit_value, bit))
+    print(f"Bit position {bit_pos:2} is {bit_value} which is worth {bit:2}.")

bitshift_example_2.py

@@ -14,14 +14,13 @@
     # Now pull each bit out of the letter.
     # Start from bit 7, and count down to 0
     for bit_pos in range(bits_to_encode - 1, -1, -1):
-
+
+        # Use bitwise and to pull out the bit we are interested in
         bit = 1 << bit_pos & my_byte
-        if bit != 0:
-            bit_value = 1
-        else:
-            bit_value = 0
-
+        # Convert to a 1 or 0, as the 1 may not be in the 1's place
+        bit_value = 0 if bit == 0 else 1
+        # Print, while staying on our current line.
         print(bit_value, end="")
 
     # Done with this letter. Go to the next line.
-    print(" - {:3} - {:}".format(my_byte, chr(my_byte)))
+    print(f" - {my_byte:3} - {chr(my_byte)}")

encode_message.py

@@ -22,7 +22,7 @@
 for my_byte in my_message:
 
     # Show what we are encoding
-    print("{} = {:3} = ".format(chr(my_byte), my_byte), end="")
+    print(f"{chr(my_byte)} = {my_byte:3} = ", end="")
 
     # Loop for each bit of the byte, starting with the most
     # significant bit 7, down to 0.
@@ -41,12 +41,8 @@
         # &      = 0100 0000 = 64 (result of bit-wise 'and')
         bit = (1 << bit_pos) & my_byte
 
-        if bit != 0:
-            # There was a value
-            bit_value = 1
-        else:
-            # There was not a value
-            bit_value = 0
+        # Make sure bit_value is a 1 or 0, not some power of 2.
+        bit_value = 0 if bit == 0 else 1
 
         print(bit_value, end="")
 

read_wire_callback.py

@@ -7,9 +7,9 @@
 # or low/high change in the signal.
 def my_callback(channel):
     if GPIO.input(channel):
-        print("Channel {} is high".format(channel))
+        print(f"Channel {channel} is high.")
     else:
-        print("Channel {} is low".format(channel))
+        print(f"Channel {channel} is low.")
 
 # Set pin 12 up for input
 GPIO.setmode(GPIO.BCM)