Want to add new condition to check Hexadecimal code


#1

Hi everyone! I was practicing with the RGB-HEX converter. After a few trial runs, I found out that the code only tests the validity of the hexadecimal input based on the length of the input (6-digit). However, what if we input an invalid 6-digits info (such as 123ABK, AJFKLD, etc.) ?

I have done some research on the internet to found out the code that will check whether users have input a hexadecimal color with characters only ranging from A to F. And i found out this solution:

import re
str = ‘#ffffff’ # Your Hex

match = re.search(r’^#(?:[0-9a-fA-F]{3}){1,2}$’, str)

if match:
print ‘Hex is valid’

else:
print ‘Hex is not valid’

Can anyone explain this to me or maybe give me a solution for my code? For example. if we input ‘A1B2CH’, the console will display ‘invalid values entered’.


def rgb_hex():
  invalid_msg = "Invalid values entered"
  red = int(raw_input("Enter red (R) value:  "))
  if (red < 0 or red > 255):
    print invalid_msg
    return 
  green = int(raw_input("Enter Green (G) value:  "))
  if (green < 0 or green > 255):
    print invalid_msg
    return 
  blue = int(raw_input("Enter Blue (B) value:  "))
  if (blue < 0 or blue > 255):
    print invalid_msg
    return
  val = (red << 16) + (green << 8) + blue
  print "Convert to Hexadecimal color:  %s" % (hex(val)[2:]).upper()
  
def hex_rgb():
  invalid_msg = "Invalid values entered"
  hex_val = raw_input("Enter Hexadecimal value:  ")
  if len(hex_val) != 6:
    print invalid_msg
    return
  else:
    hex_val = int(hex_val, 16)
  two_hex_digits = 2 ** 8
  blue = hex_val % two_hex_digits
  hex_val = hex_val >> 8
  green = hex_val % two_hex_digits
  hex_val = hex_val >> 8
  red = hex_val % two_hex_digits
  print "Convert to RGB color: %d%d%d" % (red, green, blue)

def convert():
  while True:
    option = raw_input("Enter 1 to convert RGB to HEX. Enter 2 to convert HEX to RFB. Enter X to Exit:  ")
    if option == "1":
      print "RGB to Hex. . ."
      rgb_hex()
    elif option == "2":
      print "Hex to RGB. . ."
      hex_rgb()
    elif option == "X":
      break
    else:
      print "Error"
convert()



#2

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