freeCodeCamp/curriculum/challenges/english/99-dev-playground/daily-coding-challenges-python/python-challenge-21.md

id, title, challengeType, dashedName

id	title	challengeType	dashedName
6821ecb9237de8297eaee7a3	Python Challenge 21: Hex Generator	29	python-challenge-21

--description--

Given a named CSS color string, generate a random hexadecimal (hex) color code that is dominant in the given color.

• The function should handle "red", "green", or "blue" as an input argument.
• If the input is not one of those, the function should return "Invalid color".
• The function should return a random six-character hex color code where the input color value is greater than any of the others.
• Example of valid outputs for a given input:

Input	Output
"red"	"FF0000"
"green"	"00FF00"
"blue"	"0000FF"

--hints--

generate_hex("yellow") should return "Invalid color".

({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(generate_hex("yellow"), "Invalid color")`);
}})

generate_hex("red") should return a six-character string.

({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(len(generate_hex("red")), 6)`);
}})

generate_hex("red") should return a valid six-character hex color code.

({test: () => { runPython(`
from unittest import TestCase

hex = generate_hex("red").upper()
is_valid_hex = len(hex) == 6 and all(c in "0123456789ABCDEF" for c in hex)
TestCase().assertTrue(is_valid_hex)`)
}})

generate_hex("red") should return a valid hex color with a higher red value than other colors.

({test: () => { runPython(`
from unittest import TestCase

hex = generate_hex("red").upper()
is_valid_hex = len(hex) == 6 and all(c in "0123456789ABCDEF" for c in hex)
TestCase().assertTrue(is_valid_hex)

r = int(hex[:2], 16)
g = int(hex[2:4], 16)
b = int(hex[4:], 16)

TestCase().assertGreater(r, g)
TestCase().assertGreater(r, b)`)
}})

Calling generate_hex("red") twice should return two different hex color values where red is dominant.

({test: () => { runPython(`
from unittest import TestCase

hex1 = generate_hex("red").upper()
is_valid_hex1 = len(hex1) == 6 and all(c in "0123456789ABCDEF" for c in hex1)
TestCase().assertTrue(is_valid_hex1)

r1 = int(hex1[:2], 16)
g1 = int(hex1[2:4], 16)
b1 = int(hex1[4:], 16)

TestCase().assertGreater(r1, g1)
TestCase().assertGreater(r1, b1)

hex2 = generate_hex("red").upper()
is_valid_hex2 = len(hex2) == 6 and all(c in "0123456789ABCDEF" for c in hex2)
TestCase().assertTrue(is_valid_hex2)

r2 = int(hex2[:2], 16)
g2 = int(hex2[2:4], 16)
b2 = int(hex2[4:], 16)

TestCase().assertGreater(r2, g2)
TestCase().assertGreater(r2, b2)
TestCase().assertNotEqual(hex1, hex2)`);
}})

Calling generate_hex("green") twice should return two different hex color values where green is dominant.

({test: () => { runPython(`
from unittest import TestCase

hex1 = generate_hex("green").upper()
is_valid_hex1 = len(hex1) == 6 and all(c in "0123456789ABCDEF" for c in hex1)
TestCase().assertTrue(is_valid_hex1)

r1 = int(hex1[:2], 16)
g1 = int(hex1[2:4], 16)
b1 = int(hex1[4:], 16)

TestCase().assertGreater(g1, r1)
TestCase().assertGreater(g1, b1)

hex2 = generate_hex("green").upper()
is_valid_hex2 = len(hex2) == 6 and all(c in "0123456789ABCDEF" for c in hex2)
TestCase().assertTrue(is_valid_hex2)

r2 = int(hex2[:2], 16)
g2 = int(hex2[2:4], 16)
b2 = int(hex2[4:], 16)

TestCase().assertGreater(g2, r2)
TestCase().assertGreater(g2, b2)
TestCase().assertNotEqual(hex1, hex2)`);
}})

Calling generate_hex("blue") twice should return two different hex color values where blue is dominant.

({test: () => { runPython(`
from unittest import TestCase

hex1 = generate_hex("blue").upper()
is_valid_hex1 = len(hex1) == 6 and all(c in "0123456789ABCDEF" for c in hex1)
TestCase().assertTrue(is_valid_hex1)

r1 = int(hex1[:2], 16)
g1 = int(hex1[2:4], 16)
b1 = int(hex1[4:], 16)

TestCase().assertGreater(b1, r1)
TestCase().assertGreater(b1, g1)

hex2 = generate_hex("blue").upper()
is_valid_hex2 = len(hex2) == 6 and all(c in "0123456789ABCDEF" for c in hex2)
TestCase().assertTrue(is_valid_hex2)

r2 = int(hex2[:2], 16)
g2 = int(hex2[2:4], 16)
b2 = int(hex2[4:], 16)

TestCase().assertGreater(b2, r2)
TestCase().assertGreater(b2, g2)
TestCase().assertNotEqual(hex1, hex2)`);
}})

--seed--

--seed-contents--

def generate_hex(color):

    return color

--solutions--

import random
def generate_hex(color):
    def to_hex(n):
        return hex(n)[2:].upper().zfill(2)

    dominant = random.randint(170, 255)
    weak1 = random.randint(0, 169)
    weak2 = random.randint(0, 169)

    if color.lower() == "red":
        r = dominant
        g = weak1
        b = weak2
    elif color.lower() == "green":
        r = weak1
        g = dominant
        b = weak2
    elif color.lower() == "blue":
        r = weak1
        g = weak2
        b = dominant
    else:
        return "Invalid color"

    return f'{to_hex(r)}{to_hex(g)}{to_hex(b)}'