text: """4-digit alphanumeric 7-segment display driver."""
  # Copyright (c) 2014 Adafruit Industries
  # Author: Tony DiCola
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in
  # all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  # THE SOFTWARE.
  from . import HT16K33
  
  
  # Digit value to bitmask mapping:
  DIGIT_VALUES = {
      ' ': 0b0000000000000000,
      '!': 0b0000000000000110,
      '"': 0b0000001000100000,
      '#': 0b0001001011001110,
      '$': 0b0001001011101101,
      '%': 0b0000110000100100,
      '&': 0b0010001101011101,
      '\'': 0b0000010000000000,
      '(': 0b0010010000000000,
      ')': 0b0000100100000000,
      '*': 0b0011111111000000,
      '+': 0b0001001011000000,
      ',': 0b0000100000000000,
      '-': 0b0000000011000000,
      '.': 0b0000000000000000,
      '/': 0b0000110000000000,
      '0': 0b0000110000111111,
      '1': 0b0000000000000110,
      '2': 0b0000000011011011,
      '3': 0b0000000010001111,
      '4': 0b0000000011100110,
      '5': 0b0010000001101001,
      '6': 0b0000000011111101,
      '7': 0b0000000000000111,
      '8': 0b0000000011111111,
      '9': 0b0000000011101111,
      ':': 0b0001001000000000,
      ';': 0b0000101000000000,
      '<': 0b0010010000000000,
      '=': 0b0000000011001000,
      '>': 0b0000100100000000,
      '?': 0b0001000010000011,
      '@': 0b0000001010111011,
      'A': 0b0000000011110111,
      'B': 0b0001001010001111,
      'C': 0b0000000000111001,
      'D': 0b0001001000001111,
      'E': 0b0000000011111001,
      'F': 0b0000000001110001,
      'G': 0b0000000010111101,
      'H': 0b0000000011110110,
      'I': 0b0001001000000000,
      'J': 0b0000000000011110,
      'K': 0b0010010001110000,
      'L': 0b0000000000111000,
      'M': 0b0000010100110110,
      'N': 0b0010000100110110,
      'O': 0b0000000000111111,
      'P': 0b0000000011110011,
      'Q': 0b0010000000111111,
      'R': 0b0010000011110011,
      'S': 0b0000000011101101,
      'T': 0b0001001000000001,
      'U': 0b0000000000111110,
      'V': 0b0000110000110000,
      'W': 0b0010100000110110,
      'X': 0b0010110100000000,
      'Y': 0b0001010100000000,
      'Z': 0b0000110000001001,
      '[': 0b0000000000111001,
      '\\': 0b0010000100000000,
      ']': 0b0000000000001111,
      '^': 0b0000110000000011,
      '_': 0b0000000000001000,
      '`': 0b0000000100000000,
      'a': 0b0001000001011000,
      'b': 0b0010000001111000,
      'c': 0b0000000011011000,
      'd': 0b0000100010001110,
      'e': 0b0000100001011000,
      'f': 0b0000000001110001,
      'g': 0b0000010010001110,
      'h': 0b0001000001110000,
      'i': 0b0001000000000000,
      'j': 0b0000000000001110,
      'k': 0b0011011000000000,
      'l': 0b0000000000110000,
      'm': 0b0001000011010100,
      'n': 0b0001000001010000,
      'o': 0b0000000011011100,
      'p': 0b0000000101110000,
      'q': 0b0000010010000110,
      'r': 0b0000000001010000,
      's': 0b0010000010001000,
      't': 0b0000000001111000,
      'u': 0b0000000000011100,
      'v': 0b0010000000000100,
      'w': 0b0010100000010100,
      'x': 0b0010100011000000,
      'y': 0b0010000000001100,
      'z': 0b0000100001001000,
      '{': 0b0000100101001001,
      '|': 0b0001001000000000,
      '}': 0b0010010010001001,
      '~': 0b0000010100100000
  }
  
  
  class AlphaNum4(HT16K33.HT16K33):
      """Alphanumeric 14 segment LED backpack display."""
  
      def __init__(self, **kwargs):
          """Initialize display.
  
          All arguments will be passed to the HT16K33 class initializer,
          including optional I2C address and bus number parameters.
  
          """
          super(AlphaNum4, self).__init__(**kwargs)
  
      def set_digit_raw(self, pos, bitmask):
          """Set digit at position to raw bitmask value.
  
          Position should be a value of 0 to 3 with 0 being the left most digit on the display.
  
          """
          if pos < 0 or pos > 3:
              # Ignore out of bounds digits.
              return
          # Set the digit bitmask value at the appropriate position.
          # Also set bit 7 (decimal point) if decimal is True.
          self.buffer[pos * 2] = bitmask & 0xFF
          self.buffer[pos * 2 + 1] = (bitmask >> 8) & 0xFF
  
      def set_decimal(self, pos, decimal):
          """Turn decimal point on or off at provided position.
  
          Position should be a value 0 to 3 with 0 being the left most digit on the display.
          Decimal should be True to turn on the decimal point and False to turn it off.
  
          """
          if pos < 0 or pos > 3:
              # Ignore out of bounds digits.
              return
          # Set bit 14 (decimal point) based on provided value.
          if decimal:
              self.buffer[pos * 2 + 1] |= (1 << 6)
          else:
              self.buffer[pos * 2 + 1] &= ~(1 << 6)
  
      def set_digit(self, pos, digit, decimal=False):
          """Set digit at position to provided value.
  
          Position should be a value of 0 to 3 with 0 being the left most digit on the display.
          Digit should be any ASCII value 32-127 (printable ASCII).
  
          """
          self.set_digit_raw(pos, DIGIT_VALUES.get(str(digit), 0x00))
          if decimal:
              self.set_decimal(pos, True)
  
      def print_str(self, value, justify_right=True):
          """Print a 4 character long string of values to the display.
  
          Characters in the string should be any ASCII value 32 to 127 (printable ASCII).
  
          """
          # Calculcate starting position of digits based on justification.
          pos = (4 - len(value)) if justify_right else 0
          # Go through each character and print it on the display.
          for i, ch in enumerate(value):
              self.set_digit(i + pos, ch)
  
      def print_number_str(self, value, justify_right=True):
          """Print a 4 character long string of numeric values to the display.
  
          This function is similar to print_str but will interpret periods not as
          characters but as decimal points associated with the previous character.
  
          """
          # Calculate length of value without decimals.
          length = len(str(value).replace(".", ""))
          # Error if value without decimals is longer than 4 characters.
          if length > 4:
              self.print_str('----')
              return
          # Calculcate starting position of digits based on justification.
          pos = (4 - length) if justify_right else 0
          # Go through each character and print it on the display.
          for i, ch in enumerate(value):
              if ch == '.':
                  # Print decimal points on the previous digit.
                  self.set_decimal(pos - 1, True)
              else:
                  self.set_digit(pos, ch)
                  pos += 1
  
      def print_float(self, value, justify_right=True):
          """Print a numeric value to the display.
  
          If value is negative it will be printed with a leading minus sign.
          Decimal digits is the desired number of digits after the decimal point.
  
          """
          decimal_digits = 4 - len(str(int(value)))
          format_string = '{{0:0.{0}F}}'.format(decimal_digits)
          self.print_number_str(format_string.format(value), justify_right)
  
      def print_hex(self, value, justify_right=True):
          """Print a numeric value in hexadecimal.
  
          Value should be from 0 to FFFF.
  
          """
          if value < 0 or value > 0xFFFF:
              # Ignore out of range values.
              return
          self.print_str('{0:X}'.format(value), justify_right)
  
      def show(self):
          """Display buffer on display."""
          self.write_display()
  