Print colored visual diff in Python

diff_strings.py

import difflib
import wasabi

def diff_strings(a, b):
    output = []
    matcher = difflib.SequenceMatcher(None, a, b)
    for opcode, a0, a1, b0, b1 in matcher.get_opcodes():
        if opcode == "equal":
            output.append(a[a0:a1])
        elif opcode == "insert":
            output.append(color(b[b0:b1], fg=16, bg="green"))
        elif opcode == "delete":
            output.append(color(a[a0:a1], fg=16, bg="red"))
        elif opcode == "replace":
            output.append(color(b[b0:b1], fg=16, bg="green"))
            output.append(color(a[a0:a1], fg=16, bg="red"))
    return "".join(output)
    
print(diff_strings("helloo world", "hello world!"))

Nice! Also, I think the import should be from wasabi import color.

Thanks for this Ines. If it's of interest, here's my remake which avoids the wasabi dependency and allows you to compare any two values in a list of strings:

import difflib

def diff(string_list, index_a=0, index_b=None, print_only=True):
    """
    Print or return a colour-coded diff of two items in a list of strings.
    Default: Compare first and last strings; print the output; return None.
    """
    index_b = index_b or len(string_list) -1
    green = '\x1b[38;5;16;48;5;2m'
    red = '\x1b[38;5;16;48;5;1m'
    end = '\x1b[0m'
    output = []
    string_a = string_list[index_a]
    string_b = string_list[index_b]
    matcher = difflib.SequenceMatcher(None, string_a, string_b)
    for opcode, a0, a1, b0, b1 in matcher.get_opcodes():
        if opcode == "equal":
            output += [string_a[a0:a1]]
        elif opcode == "insert":
            output += [green + string_b[b0:b1] + end]
        elif opcode == "delete":
            output += [red + string_a[a0:a1] + end]
        elif opcode == "replace":
            output += [green + string_b[b0:b1] + end]
            output += [red + string_a[a0:a1] + end]
    output = "".join(output)
    if not print_only:
        return output
    print(f"\n{output}\n")

Same API as original post:

import difflib

def diff_strings(a: str, b: str, *, use_loguru_colors: bool = False) -> str:
    output = []
    matcher = difflib.SequenceMatcher(None, a, b)
    if use_loguru_colors:
        green = '<GREEN><black>'
        red = '<RED><black>'
        endgreen = '</black></GREEN>'
        endred = '</black></RED>'
    else:
        green = '\x1b[38;5;16;48;5;2m'
        red = '\x1b[38;5;16;48;5;1m'
        endgreen = '\x1b[0m'
        endred = '\x1b[0m'

    for opcode, a0, a1, b0, b1 in matcher.get_opcodes():
        if opcode == 'equal':
            output.append(a[a0:a1])
        elif opcode == 'insert':
            output.append(f'{green}{b[b0:b1]}{endgreen}')
        elif opcode == 'delete':
            output.append(f'{red}{a[a0:a1]}{endred}')
        elif opcode == 'replace':
            output.append(f'{green}{b[b0:b1]}{endgreen}')
            output.append(f'{red}{a[a0:a1]}{endred}')
    return ''.join(output)

print(diff_strings('helloo world', 'hello world!'))

from loguru import logger
logger.opt(raw=True, colors=True).info(diff_strings('helloo world', 'hello world!', use_loguru_colors=True))