Ensure print() does not wrap with long inputs

Eg. if only 1 display is available, shouldn't try to print more than 4 characters
Also fix initialization of display_RAM, should be zeros instead of spaces

Author: sfe-SparkFro

qwiic_alphanumeric.py

@@ -232,7 +232,7 @@ class QwiicAlphanumeric(object):
     colon_on_off = 0    # Tracks the on/off state of the colon segment
     blink_rate = ALPHA_BLINK_RATE_NOBLINK   # Tracks the current blinking status
 
-    display_RAM = [' '] * 16 * 4
+    display_RAM = [0] * 16 * 4
     display_content = [' '] * (4 * 4 + 1)
 
     def __init__(self, address=None, i2c_driver=None):
@@ -966,7 +966,7 @@ def print(self, print_string):
 
         self.digit_position = 0
 
-        for i in range(0, len(print_string)):
+        for i in range(0, min(len(print_string), self.number_of_displays * 4)):
             # For special characters like '.' or ':', do not increment the digit position
             if print_string[i] == '.':
                 self.print_char('.', 0)
@@ -978,7 +978,6 @@ def print(self, print_string):
                 self.display_content[i] = print_string[i]
 
                 self.digit_position = self.digit_position + 1
-                self.digit_position = self.digit_position % (self.number_of_displays * 4)
 
         self.update_display()