تجنب القائمة المشتركة في المعاملات الإفتراضية للدوال

def add_skill(skill, skills=[]):
    skills.append(skill)
    return skills

print(add_skill("HTML"))
print(add_skill("Python"))

['HTML']
['HTML', 'Python']

def add_skill(skill, skills=None):
    if skills is None:
        skills = []
    skills.append(skill)
    return skills

print(add_skill("HTML"))
print(add_skill("Python"))

['HTML']
['Python']